During his stay in the German capital, Ukrainian presidential candidate Petro Poroshenko justified the use of violence by his country's army against pro-Russian separatists, whom he described as "terrorists."

Poroshenko clarified that those who carry machine guns and kill people understand only one language, "that of force." He rejected calls to take up negotiations with separatists. "They don't represent anybody. We have to restore law and order and sweep the terrorists off the street," said the confectionery-magnate-turned-politician who is a frontrunner at Ukrainian elections slated for May 25.

In Berlin, Poroshenko welcomed a suggestion by German Foreign Minister Frank-Walter Steinmeier (SPD) to hold a second round of talks in Geneva. But the 48-year-old said he did not want any pro-Russian separatists at the table, adding that the only legitimate representative of Ukraine was the country's foreign minister.

Elections as planned

Poroshenko said the upcoming elections were a vital step and had to be held throughout Ukraine. "Those who try to destabilize the situation in the east of Ukraine have only one intention: they want to prevent us from holding elections," said Poroshenko. "Fake referendums" in eastern Ukraine, he added, had to prevented - such as the referendum in Donetsk on a secession of the region, which is scheduled for next Sunday.

"We are not afraid of referendums, constitutional changes or a decentralization of power," said Poroshenko, who had meetings in Berlin with Chancellor Angela Merkel, Foreign Minister Frank-Walter Steinmeier and members of the German parliament. But he added that presidential elections had to be held first and those issues could then be addressed in an appropriate manner afterwards.

German conservative politician Andreas Schockenhoff (CDU) said after the meeting with Poroshenko that it was "illegal" to hold any kind of a referendum ahead of the elections. He added there were indications that May 9 and 11 could see "heckling activities," possibly with Russian involvement. Schockenhoff urged Russia to refrain from any attempt to destabilize Ukraine.

Topical debate at Bundestag

Among those expressing their concern over violent clashes in Ukraine were two German ministers. "We're on the brink of a new confrontation on our continent," said Foreign Minister Steinmeier in a last-minute Bundestag debate. He added he was still optimistic that it "wasn't too late" to stop an escalation of the situation, adding that he was currently busy trying to set up a second round of Geneva talks.

Steinmeier said it was in Moscow's interest, too, since the Russian government doubted the legitimacy of the current Ukrainian interim government. He also called for national dialog within Ukraine to overcome tensions. He said he was in favor of a constitutional reform and for the disarmament of the militia. During the minister's speech, news broke that Russian President Vladimir Putin had given up his opposition to the elections. For the first time, Putin called the presidential elections a "step in the right direction."

Presidential candidate Poroshenko told DW in Berlin on Thursday evening that he welcomed Putin's statement, but he also warned it was not yet a guarantee that the situation had been stabilized.

Discussion about OSCE mission

The German foreign minister vehemently rejected criticism of the OSCE observation that came from conservative member of parliament Peter Gauweiler and members of the opposition. Wolfgang Gehrcke, of the Left Party, commented that the military observers' mission had endangered the much bigger and more important civilian mission, which involved 500 OSCE observers and was agreed by all sides.

Two weeks ago, during their deployment in eastern Ukraine, the seven-man group of soldiers under German leadership were arrested in the city of Donetsk by separatists. They were detained for one week and only released last Saturday. Steinmeier and German Defense Minister Ursula von der Leyen (CDU) thanked those involved in getting the men home safely.

They explicitly mentioned Russian Commissioner on human rights, Vladimir Lukin. Von der Leyen stressed that the OSCE observers' mission had been set up with the goal of creating trust and transparency in conflict situations.

Criticism of Putin

Green member of Parliament Marie-Luise Beck criticized Russia in strong terms. Moscow was actively working on destabilizing Ukraine and on immersing its neighboring country in a civil war, she said. At the same time, civil society was dwindling in Russia, Beck added, because of the attempts by the country's president Vladimir Putin to combat a liberal and multicultural society.

Instead, Putin actively sought collaboration with right-wing populists from across Europe. Beck stressed that the secession and occupation of Crimea by Russia ought not be condoned. For the first time since 1945, Beck said, a part of a sovereign country had been annexed by force from outside.