MOSCOW--President Vladimir V. Putin of Russia reportedly told a European official that he could “take Kiev in two weeks” if he wanted to, adding a new dimension to the tensions building in Ukraine as Russian forces become more involved in the fighting there.

As NATO leaders gather in Wales for a summit meeting, Mr. Putin’s remarks and the increasing presence of Russian military units in Ukraine have posed a stark new challenge to the alliance about how to respond to Moscow’s apparent willingness to exert military force to achieve its foreign policy goals.

The Kremlin did not deny the remark, which was published in the Italian newspaper La Repubblica on Monday, but on Tuesday it denounced the European official, José Manuel Barroso, for leaking details of what Mr. Putin understood to be a private telephone call.

“Whether these words were said or not, in my viewpoint, the quote given is taken out of context, and it had an absolutely different meaning,” said Yuri Ushakov, a Kremlin aide, according to the Interfax news service.

It was the first Kremlin response to the article, in which Mr. Barroso, the president of the European Commission, relayed Mr. Putin’s response to his question of whether Russian troops had crossed into eastern Ukraine.

“That is not the question,” Mr. Barroso said Mr. Putin told him. “But if I wanted to, I could take Kiev in two weeks.”

On Tuesday evening, Vladimir Chizhov, the Russian envoy to the European Union, said that Russia had both an audio recording and a written record of the conversation, and he issued Mr. Barroso a two-day ultimatum about their release to “dispel any misunderstandings.”

Mr. Putin is known for littering his public statements with twists of braggadocio, immortalized in a vow he made as prime minister in 1999 to root out terrorism in Russia.

“If we catch them in the toilet, we’ll whack them in the outhouse,” he said of the terrorists then.

On Tuesday, however, Mr. Ushakov said that it was Mr. Barroso who was out of line if he had relayed a diplomatic conversation to the newspaper.

“It appears to me to be simply unworthy of a serious political figure,” he said.

The war of words has expanded across Europe in advance of the NATO summit meeting on Thursday and Friday, when the alliance’s leaders are expected to endorse a rapid-reaction force of 4,000 troops for Eastern Europe.

That prompted a senior Russian military official to announce that the country would revise its military doctrine to account for “changing military dangers and military threats,” including, he said, NATO expansion.

In an interview with the state news agency RIA Novosti released on Tuesday morning, the official, Mikhail Popov, the deputy secretary for Russia’s Security Council, called the expansion of NATO “one of the leading military dangers for the Russian Federation.”

The Kremlin has long bridled over NATO’s expansion into Eastern Europe, with officials angrily accusing Western officials of double-crossing them by admitting countries like Poland and the Baltic States after assuring them it would never happen.

NATO member states have shared a border with the Russian enclave of Kaliningrad since Poland’s accession to the alliance in 1999, and with mainland Russia since the Baltic states of Estonia and Latvia joined in 2004. Poland and the Baltic states have recently lobbied NATO to station alliance troops in the region permanently.

Foreign Minister Sergey V. Lavrov, speaking at a news conference in Moscow, said that a recent initiative by the Ukrainian government to shed the country’s nonaligned status and join the military alliance could scuttle efforts to negotiate a peace settlement between Kiev and separatists in the country’s southeast.

He added that hawkish rhetoric in the Ukrainian government, including talk on Tuesday of a “Great Patriotic War” along the lines of World War II, was being “incited from Washington, some European capitals and more and more often from Brussels and from NATO headquarters, where the North Atlantic alliance secretary general gives statements with and without cause.”

Mr. Popov said that Russia expected NATO leaders this week to try to strengthen their long-term military presence in Eastern Europe by establishing new military bases in the region and deploying tanks in Estonia, a NATO member that borders Russia.

“We believe that the defining factor in our relationship with NATO remains the unacceptability for Russia of plans to move military infrastructures of the alliance to our borders, including by means of expanding the bloc,” Mr. Popov said.

President Obama is scheduled to visit Estonia before the NATO summit meeting to highlight the United States’ commitment to the military alliance and the alliance’s determination to protect all 28 members from aggression, from Moscow or elsewhere.

Mr. Putin has often bristled at NATO expansion in public comments, and has said that the alliance’s potential expansion into a post-revolutionary Ukraine encouraged Russia to annex Crimea.

At a nationally televised call-in show in April, Mr. Putin said that “when the infrastructure of a military bloc approaches our borders, we have grounds for certain apprehensions and questions.”

“We wanted to support the residents of Crimea, but we also followed certain logic: If we don’t do anything, Ukraine will be drawn into NATO sometime in the future,” Mr. Putin said, adding that “NATO ships will dock in Sevastopol, the city of Russia’s naval glory.”

Mr. Popov, the military adviser, also said that Russia believed it had sufficient forces in Crimea, the peninsula that Russia annexed in March, “to repel an invasion from a potential aggressor on the territory of the republic.”

“Crimea today is the territory of the Russian Federation, and armed aggression against Crimea will be seen as aggression against the Russian Federation, with all of the resulting consequences,” Mr. Popov said. (Source: The New York Times)

Story Date: September 3, 2014