The United States, Britain, and Ukraine are calling for direct talks between Ukraine and Russia, saying they are crucial to resolving the conflict in Ukraine's Crimean region.
The foreign ministers of those three countries, including U.S. Secretary of State John Kerry, issued a joint statement Wednesday after talks in Paris. They also called for international observers to be deployed immediately in eastern Ukraine and Crimea, near the Russian border.
Russian Foreign Minister Sergei Lavrov was also in Paris for the talks by the so-called Budapest agreement group, but did not attend the meeting. Under the 1994 agreement, the United States, Britain and Russia are to support Ukraine's territorial integrity.
The State Department said Kerry spoke privately with Lavrov and urged him to engage in talks with his new counterpart from Ukraine, interim foreign minister Andriy Deshchytsia.
Meanwhile, NATO Secretary-General Anders Fogh Rasmussen announced the alliance will review its cooperation with Russia, while increasing its engagement with Ukraine's civilian and military leadership.
He also said NATO has suspended planning for a joint mission with Russia to protect a U.S. ship that will destroy Syrian chemical weapons.
British Foreign Secretary William Hague said earlier the United States and Britain are pursuing "every diplomatic opportunity" to bring Russian and Ukrainian officials into contact with each other.
Hague said there will be "costs and consequences" for Russia if diplomatic progress is not made. He said Russia understand that its pattern of intervening in countries like Ukraine, Georgia and Moldova will change its relationship with European nations.
Meanwhile, Russian President Vladimir Putin was quoted as saying he does not want the "political tension" between Russian and Ukraine to detract from economic cooperation between the two countries.
Western leaders have been calling for a de-escalation of tensions sparked when Russian forces moved into Ukraine's Crimean peninsula late last week. The West has suggested the crisis could be resolved if Russia pulls back its forces to their bases on the Black Sea and allows in international monitors.
But Lavrov said Wednesday that Russia cannot order pro-Russian armed forces in Crimea, which he described as "self-defense" forces, back to bases, because they are not Russian forces.
And he said allowing international monitors into Crimea is not Russia's decision, but the decision of Ukrainian and Crimean authorities.
Ukraine's new prime minister Arseniy Yatsenyuk told the Associated Press he would like a special task force established to discuss Crimea's status.
"Crimea is, was, and will be an integral part of the state of Ukraine. We believe that we need to establish a task force to establish what kind of additional autonomy Crimea could get."
He blamed Mr. Putin for the region's current unrest and said Ukrainian leaders "cannot figure out" why Mr. Putin has sent Russian troops into Crimea. He expressed fear that Russia could expand its presence to other Russian-speaking parts of Ukraine.
Crimea is set to hold a referendum on its future status on March 30. Ethnic Russians make up nearly 60-percent of the peninsula's population.