The EU and the US have announced new sanctions against prominent Russians, including close allies of President Vladimir Putin, as Moscow raced to complete its annexation of Crimea.
The European bloc on Friday announced it was expanding its list of Russians targeted with sanctions by 12, hours after the US president, Barack Obama, said his administration had imposed sanctions on "senior officials" in the Kremlin.
Moscow on Thursday announced its own sanctions against senior US politicians in retaliation against visa bans and asset freezes imposed by Washington on its citizens.
Speaking at the White House, Obama said Russia's threats to southern and eastern areas of Ukraine - which like Crimea have large Russian-speaking populations - posed a serious risk of escalating the crisis in the region.
"We're imposing sanctions on more senior officials of the Russian government," he said.
"In addition, we are today sanctioning a number of other individuals with substantial resources and influence who provide material support to the Russian leadership, as well as a bank that provides material support to these individuals."
Duma approves annexation
The president's remarks came after the Russian parliament's lower house gave its near-unanimous approval to the country's annexation of Crimea, ignoring threats of more sanctions.
The Kremlin-controlled Duma voted 445-1 on Thursday to make Crimea a part of Russia following a quick discussion in which members assailed the Ukrainian authorities.
The vote came as UN Secretary-General Ban Ki-moon arrived in Moscow for a meeting with Putin. "I'm deeply concerned about the current situation," Ban said at the start of the talks.
The incorporation of Crimea into Russia needs to be rubber-stamped by the upper house and receive a final endorsement by Putin, formalities expected to be completed by the end of the week.
|UN Secretary General seeks solution to Crimea crisis
During Thursday's debate, senior politicians spoke of the need to protect Russian speakers elsewhere in Ukraine from radical Ukrainian nationalists, statements that could fuel fears of Russian invasion.
"They don't understand in Washington that entire territories will flee as Crimea did if such outrage continues," said Vladimir Vasilyev, the leader of the dominant United Russia faction.
Though Putin, who signed the treaty for Crimea to join Russia earlier this week, said he is not seeking a division of Ukraine, he insists the country can "use all means" to protect Russian speakers.
He also made his view clear that he sees Ukraine as an artificial state carved up by the Soviet government to include some of Russia's historic lands.
Russia has been arguing for broad autonomy for Ukraine's regions that would turn the nation into a federation, and guarantees of Ukraine's neutral status to prevent its membership in NATO.
Thursday's Duma vote follows Crimea's referendum on Sunday, which was held just two weeks after Russian forces effectively took over the strategic Black Sea peninsula. The United States and the European Union have responded by slapping some limited sanctions on Russia.
Ilya Ponomarev, an opposition lawmaker who was the only Duma member who voted against the move, said in his blog that Russia behaved like a "banal aggressor" and made a grave mistake by annexing Crimea.