U.S. Vice President Joe Biden arrived in Poland on Tuesday in the first of several visits meant to bolster confidence in NATO nations that border Russia.
Poland and the Baltic nations are growing increasingly concerned that Russia could turn its military on them, following the all-but-certain annexation of the Crimean Peninsula, according to Reuters.
Russian President Vladimir Putin on Tuesday moved to formally adopt Crimea under Moscow's control, ignoring threats of further sanctions from Europe and the United States.
Putin signed a draft document on annexing the area, which Russian forces have been occupying since the beginning of the month. Russia's Constitutional Court and its Kremlin-dominated legislature are anticipated to rapidly approve the move, with some lawmakers forecasting that Crimea could officially become part of Russia before the week is over, the Associated Press reported.
A Sunday referendum in Crimea on seceding from Ukraine was overwhelmingly approved. Putin has threatened to utilize "all means" to safeguard ethnic Russians living in eastern Ukraine, though Moscow has reportedly agreed to refrain until the end of the week from attacking any Ukrainian military sites.
Meanwhile, Russian weapon inspectors were scheduled to arrive in the United States on Monday in order to conduct an onsite visit of U.S. nuclear weapon facilities in accordance with the New START accord, the Washington Free Beacon reported. The visit shows Moscow does not plan on halting such reciprocal inspections, though unnamed senior Russian military officials earlier threatened to do so. Russian Defense Minister Anatoly Antonov recently said Moscow would continue to comply with the bilateral strategic arms control treaty regardless of East-West tensions over Ukraine.
Still, Putin's actions in the last day suggest the new sanctions announced on Monday by the European Union and the United States have done little to deter him. The announced asset freezes and travel bans affect a slew of Russian and Crimean officials, but left some in Putin's inner circle untouched for now, allowing room for possible future sanctions, according to the New York Times.
In remarks before the Russian parliament on Tuesday, the president attempted to convince Ukrainians that Moscow did not plan further incursions into their country, Reuters reported.
"Don't believe those who try to frighten you with Russia and who scream that other regions will follow after Crimea," Putin said. "We do not want a partition of Ukraine. We do not need this."
Earlier in the day, Ukraine's interim prime minister, Arseniy Yatseniuk, in an apparent attempt to soothe Moscow, said Kiev was not interested in joining NATO.
White House Press Secretary Jay Carney on Monday told journalists the Obama administration was assessing a request from Kiev for military assistance, but that the government was presently keeping all aid confined to economic support, Reuters separately reported.