The head of Russia's mercenary Wagner Group threatened to withdraw his troops from the embattled city of Bakhmut in Ukraine amid heavy casualties.

Yevgeny Prigozhin told military blogger Semyon Pegov losses were five times higher than necessary because of the lack of artillery ammunition.

"Every day, we have stacks of thousands of bodies that we put in coffins and send home," Prigozhin said in the interview published on Saturday. 

He had written to Russian Defense Minister Sergei Shoigu asking for supplies. "If the ammunition deficit is not replenished, we are forced, in order not to run like cowardly rats afterwards, to either withdraw or die."

Wagner has been spearheading Russia's assault on Bakhmut but Ukrainian defenders have been able to hold onto part of the city. 

Casualties are high on both sides.

Prigozhin had previously claimed that the Russian military was withholding ammunition from his soldiers.

He charged ammunition stockpiles were withheld because of "treason" by Russian officials.

Last week he expressed concern about a counter-attack by well-equipped Ukrainian troops at Bakhmut.

Here are some of the other headlines concerning Russia's war in Ukraine on Saturday, April 29:

More German military aid needed 'urgently'

Ukraine is appealing for Germany to quickly send more air defense systems, tanks and ammunition, Kyiv's top diplomat to Germany said in an interview published on Saturday.

Ambassador Oleksii Makeiev said the heavy weapons and equipment are needed as Ukraine's military prepares to launch a counteroffensive to retake territory seized by Russian troops.

"More air defense systems — like the IRIS-T, Patriot and Gepard — are needed most urgently," Makeiev told the newspapers of Germany's Funke media group.

"For the planned counteroffensive, we need more armored vehicles, tanks and artillery systems, long-range ammunition in the shortest possible time," he added.

Ukrainian President Volodymyr Zelenskyy also urged allies to help bolster air defense systems following a series of deadly Russian missile strikes on Friday. At least 25 people were killed in the attacks on residential areas, including several children.

Zelenskyy said Ukraine's military was able to shoot down many of the Russian missiles but that the strikes show "that we can stop terror and save people only with weapons."

So far, Germany has delivered 18 Leopard 2A6 main battle tanks, 40 Marder infantry fighting vehicles and 34 Gepard anti-aircraft tanks — as well as Patriot and IRIS-T air defense systems.

Ukraine protests Warsaw agricultural bans

Ukraine has protested what it described as "categorically unacceptable" bans against the transit of its agricultural produce through neighboring Poland, as the war continues to challenge produce routes out of the country.

The Foreign Ministry said on Saturday that it sent a formal note to the Polish and European Union representatives in the country a day before regarding the bans.

Poland and other Ukrainian neighbors have recently imposed temporary trade barriers on grains and other goods. The bans followed protests by local farming after a drop in the prices of local produce.

"There are full legal grounds for the immediate resumption of exports of Ukrainian agricultural goods to Poland, Romania, Hungary, Slovakia and Bulgaria, as well as the continuation of unhindered exports to other EU member states," the Ukrainian ministry said.

Meanwhile on Friday, the EU announced reaching an agreement "in principle" with Ukraine's neighbors Bulgaria, Hungary, Poland, Romania and Slovakia regarding the passage of produce.

Russia: Huge fire at Crimea fuel depot after drone strike

Russian authorities in annexed Crimea reported a massive fire at a fuel depot in the military port city of Sevastopol early on Saturday. 

"According to preliminary information, it was caused by a drone strike," said the Russian-installed governor of the peninsula, Mikhail Razvozhayev. 

He said that a level four alert, the highest available, had been activated. 

Razvozhayev said that "these reserves were not used for petrol station deliveries," and thus the fire would not threaten fuel supplies, suggesting the depot was used for military purposes. 

Razvozhayev said that civilian infrastructure had not been threatened and 18 firefighting units had been deployed.

He did not say whether the drone he cited as causing the fire was Ukrainian.

Ukraine has not acknowledged involvement in any of several attacks in Crimea since  Russia's full scale invasion of the rest of Ukraine last year, sometimes implying a domestic insurgency.

Ukrainian military intelligence spokesperson Andriy Yusov told the Ukrainian RBC website that the blast was "God's punishment" to Russia for its deadly attacks on Ukrainian cities the prior day. Yusov said the detonation destroyed over 10 tanks of oil products, with a total capacity of some 40,000 tons. 

Yusov, however, did not explicitly say that Ukraine was responsible for the explosion.    

South Korea 'considering various options' for aid to Ukraine

South Korean President Yoon Suk -yeol said his country is weighing options when it comes to providing lethal aid to Ukraine.

So far, South Korea has delivered economic and humanitarian aid to Ukraine but has not yet moved to send weapons or ammunition.

"We are closely monitoring the situation that's going on the battlefield in Ukraine and will take proper measures in order to uphold the international norms and international law," the South Korean leader said in a speech at Harvard University in the US.

"Right now we are closely monitoring the situation and we are considering various options," he said.

Spring offensive preparation nearly complete, says Kyiv

Ukraine's defense minister said preparations for a planned counterassault against Russian forces are nearly complete now that pledged equipment has been "partially delivered."

"Preparations are coming to an end," Reznikov said. 

"As soon as there is God's will, the weather and the decision of the commanders — we will do it," he added.

Ukraine plans on soon launching a major ground operation against Russian forces, armed with hundreds of tanks and armored vehicles sent by allies.

Kyiv is seeking to retake eastern and southern areas of Ukraine that are occupied by Russia.

Ukrainian counterassault 'needs to wait,' security expert tells DW

Kyiv's plans to launch a massive ground assault to push back Russian troops have been delayed due to a number of issues, Andras Racz, a senior fellow at the German Council on Foreign Relations, told DW.

Russian fortifications, Ukraine's shortage of ammunition, Kyiv's lack of experience in coordinating such an offensive and constant rain for several months have been complicating the start. 

"The counteroffensive still needs to wait," he concluded, referring to the conditions on the ground.  

When asked about the possibility of success of such an offensive, the security fellow estimated that there was "a significant chance" of such, however a lot would "depend on the brigade commanders, battalion commanders and how this combined arms operation is conducted." 

Russia's current priorities were to "put the Russian flag on the ruins of Bakhmut on the 9th of May," the "so-called victory day commemorating Soviet victory in the Second World War," Racz said.

However, once the counteroffensive would start, "Russia will concentrate all their resources, all their weapons to stop the counteroffensive, including, of course, long-range missile and cruise missile strikes," he said.

Deal reached in resuming Ukraine grain transit

The European Commission announced that it reached an agreement on Friday with several eastern European countries over agricultural imports from Ukraine.

Tensions had risen after several EU member states — Hungary, Slovakia, Bulgaria and Poland — began limiting Ukrainian grain imports, saying that it was causing market distortion.

The situation has also sparked tensions in Romania.

Under the agreement, the countries agreed to drop their import curbs in exchange for "exceptional safeguard measures" for wheat, maize, rapeseed and sunflower seeds, Commission Vice-President Valdis Dombrovskis wrote on Twitter.

Further details on the deal were not immediately available.

Ukraine had sharply criticized the grain import restrictions, saying it sends a dangerous signal about European solidarity.

European allies visit Ukraine in show of support

The leaders and top diplomats from several European countries visited Ukraine on Friday for talks on military aid.

Ukrainian Foreign Minister Dmytro Kuleba hosted a meeting with seven other foreign ministers in the southern port city of Odesa. The top diplomats of Denmark, Sweden, Iceland, Norway, Estonia, Latvia and Lithuania took part.

"Through this visit, we manifest strong Nordic and Baltic support for Ukraine and its people," said Swedish Foreign Minister Tobias Billstrom, whose country currently holds the rotating six-month EU presidency.

Meanwhile, in the Ukrainian capital Kyiv, President Volodymyr Zelenskyy met with his Slovakian and Czech counterparts, where they discussed military aid deliveries to prepare for Ukraine's counteroffensive.

More DW content on Russia's war in Ukraine

Following Chinese President Xi Jinping's first phone call with his Ukrainian counterpart, Volodymyr Zelenskyy, since Russia's invasion, analysts say little has changed in Beijing's policy. Some experts told DW that the move was less about addressing European concerns, but more about serving Beijing's own interests.

A survey commissioned by DW shows a broad range of opinion among Russian speakers in Germany on the Ukraine war. For the full results of the survey, and to find out what Russian speakers living in Berlin had to say, you can watch the full report below.

lo, rs/sri (AP, AFP, dpa, Reuters)