WARSAW -- Vice President Joe Biden called Russia's move into Crimea "nothing more than a land grab," and said the United States may boost its participation in NATO military exercises in the nearby Baltic region.
"The world has seen through Russia's actions and has rejected the flawed logic behind those actions," Mr. Biden said Tuesday in Warsaw, in the first public remarks by a U.S. official after Russian President Vladimir Putin told lawmakers in Moscow that Crimea is an "inalienable" part of Russia.
The United States and its allies are "absolutely confident that we're up to the challenge" of confronting Russia, Mr. Biden said after meeting with Polish Prime Minister Donald Tusk, who said the annexation of Crimea is "not acceptable."
"The Crimean events and Russia's unprecedented decisions aren't just a problem for Ukraine and its neighbors. Russia's actions in Crimea are a challenge to the whole world," Poland's leader said.
"We're exploring a number of additional steps to increase the pace and scope of our military cooperation, including rotating U.S. forces to the Baltic region to conduct ground and naval exercises as well as training missions," Mr. Biden said at a meeting in Warsaw with Estonian President Toomas Hendrik Ilves.
Europe must increase its support of NATO in the wake of Russia's actions, Mr. Ilves said. "The East-West relationship needs to be put on a new standing," he said.
Mr. Biden left Washington on Monday night, hours after Mr. Obama joined with European Union leaders to slap sanctions on Russian officials and Putin allies. Mr. Putin responded by recognizing Crimea as a sovereign state, following a Black Sea peninsula referendum Sunday on joining Russia. The United States and EU regard the vote as illegitimate.
Poland was Mr. Biden's first stop on a two-day show of U.S. solidarity with North Atlantic Treaty Organization allies amid the heightened tension in the region.
He said the United States and NATO can help strengthen Poland and the Baltic states militarily as well as help them diversify the region's energy supply.
In a further show of unity, Mr. Obama on Tuesday invited the heads of state from Canada, France, Germany, Italy, Japan and Britain as well as the European Union, to a meeting of Group of Seven nations Monday on the sidelines of a nuclear security summit in The Hague previously planned for Monday and Tuesday.
Leaders will discuss "further steps that the G-7 may take to respond to developments and to support Ukraine," National Security Council spokeswoman Caitlin Hayden said at the White House. G-7 nations had earlier suspended preparations for the G-8 summit in June in Sochi, Russia.
Mr. Biden also met with Polish President Bronislaw Komorowski. He meets today in Lithuania with Latvian President Andris Berzins and Lithuanian President Dalia Grybauskaite.
Mr. Putin said Tuesday that Russia doesn't intend to occupy eastern Ukraine. He blamed Western encroachment for forcing him to annex Crimea, where Russia maintains a naval base and which was Russian territory until 1954.
In the coming weeks, the United States will discuss with European partners ways to diversify their energy sources to reduce dependence on Russia. Mr. Biden said he and Mr. Tusk talked about steps Poland is taking to reverse natural gas flows in some pipelines and help neighboring Ukraine access additional gas. Mr. Biden and Mr. Tusk also discussed trans-Atlantic trade negotiations.