NATO Secretary General Jens Stoltenberg was in the United States on Tuesday for talks with US President Joe Biden and Secretary of State Antony Blinken. 

Stoltenberg told Biden at an Oval Office meeting that the "support we are providing together for Ukraine is now making a difference on the battlefield" amid the Kyiv counteroffensive.

NATO has provided Ukrainian forces with arms and weaponry over the last few months to help it take territories seized by Russia since it launched its full-scale invasion of its neighbor in February last year.

The outgoing NATO chief said earlier in the day to broadcaster CNN: "The more land they gain, the more likely it is that President Putin will understand that he has to sit down at the negotiating table and agree to a just and enduring peace in Ukraine."

Biden's root canal procedure delayed initial meeting

Biden thanked Stoltenberg for his patience and for rescheduling as the president underwent a second root canal surgery on Monday after registering dental discomfort over the weekend. 

Biden said NATO has grown more unified during Russia's war in Ukraine and "we're going to be building on that momentum" when the alliance holds its annual summit in the Lithuanian capital Vilnius on July 11 and 12.

"I had a lot of fun yesterday afternoon," Biden said. "I had a little toothache problem I took care of, and thank you for accommodating me," the president said to the NATO chief. 

Biden then referred to his last meeting with Stoltenberg in Warsaw. 

"And I think you said it, and I agree, NATO has never been more united," he said. "We both worked like hell to make that happen. And so far, so good." 

Echoing earlier comments from Secretary of State Antony Blinken, Biden said the US commitment to NATO's mutual defense pact, Article 5, was "rock solid." 

Stoltenberg meanwhile thanked Biden "most importantly for your leadership and for your strong personal commitment to the trans-Atlantic bond, to Europe and North America standing together." 

Blinken, meanwhile, thanked the outgoing NATO secretary-general "especially" for his "strong and steady hand" during "one of the most critical times that I can remember in alliance history." 

The US Secretary of State said NATO was "stronger and more unified than it's ever been" thanks in part to Stoltenberg. 

Blinken: Vilnius summit will 'reaffirm commitment to defend every inch of NATO territory'

Stoltenberg said his talks in the US were part of broader preparations for the upcoming NATO leaders' summit in Vilnius in July.

Blinken told reporters that he anticipated the alliance would "reaffirm its shared commitment to Article 5 and to defending every inch of NATO territory" at the summit. 

He also said he anticipated a "robust package of political and practical support" for Ukraine, as well as commitments on defense spending and expanding defensive capabilities. 

"We believe as well that it is the time to welcome Sweden as the next member of the alliance," Blinken said, after Hungary and particularly Turkey hadslowed that process in recent months. 

In Europe, French President Emmanuel Macron, German Chancellor Olaf Scholz and Polish President Andrzej Duda discussed Ukraine's counteroffensive in Paris on Monday evening. 

Stoltenberg: Counteroffensive could help force peace talks

Ahead of Tuesday's political appointments, Stoltenberg spoke to US news channel CNN about the uptick in fighting in Ukraine as authorities in Kyiv say their long-awaited counteroffensive has started in earnest. 

He said it was still "early days" for the attempted thrust and conceded the situation remained "difficult." 

"They have the right to... liberate their own land," Stoltenberg said. 

He also hinted, as Macron did in France on Monday, that a successful Ukrainian push might even force Russia to the negotiating table on something closer to Kyiv's terms.

Heavy fighting in Ukraine: Kyiv reports gains, Putin says at high cost

Ukraine has reported gains in a push southwards along a roughly 100-kilometer (60-mile) front in the country's south and east in recent days, recapturing several villages along the line. 

Reuters news agency on Tuesday reported that its journalists had gained access to one such liberated village, Neskuchne, saying the Ukrainian flag was flying over a grocery store in the deserted village, which used to have a population of a few hundred people before Russia's invasion. 

Russian President Vladimir Putin did not dispute Ukraine's territorial gains on Tuesday, but he did claim that Kyiv's forces had incurred heavy costs to achieve them.

In a televised meeting with war correspondents and military bloggers, Putin claimed that Ukraine had lost more than 160 tanks and around a quarter of the military vehicles supplied from abroad, while Russia had lost 54 tanks. DW could not verify his assertions. 

Putin also said he saw no need for another major mobilization of reservists in the conflict. He did, however, concede that Russian authorities could have been better prepared for recent attacks across Russia's border, for which Moscow ultimately blames Kyiv, while Ukraine's government claims no involvement. 

rm, msh/rs, jsi (AFP, AP, Reuters)