Russia plans to unveil its own solution to the Ukraine crisis, a plan that is likely to run counter to U.S. proposals.
"We prepared, together with members of the Russian Security Council, our counter-proposals. They aim to resolve the situation on the basis of international law and take into account the interests of all Ukrainians without exception," Foreign Minister Sergei Lavrov said during a televised meeting with President Vladimir Putin.
At a meeting with Putin in the Black Sea resort of Sochi, Lavrov said he received proposals from U.S. Secretary of State John Kerry which "did not completely satisfy us." Lavrov also said Kerry had declined an invitation to visit Russia for further talks.
On Monday the State Department clarified Kerry's stance, saying the top U.S. diplomat needs concrete evidence that Russia will stop its military advance into Ukraine and engage seriously in American diplomatic proposals to de-escalate the crisis before meeting with Lavrov.
Moscow has consistently described the ouster of former Ukrainian president Viktor Yanukovych as the illegal overthrow of a legitimate head of state. Russian news agencies report Yanukovych is expected to make his second public appearance since stepping down and fleeing Kyiv last month on Tuesday.
Meantime, NATO will start reconnaissance flights over Poland and Romania to monitor the situation in Ukraine, the alliance said Monday. Ukraine is not a NATO member but Russia's actions in Crimea have alarmed neighboring countries, including alliance members that used to be dominated by the Soviet Union.
Russian forces have tightened their grip on Crimea as authorities in the breakaway territory push their proposal to join Moscow, a decision it plans to put to a referendum on March 16.
The U.S. ambassador to Ukraine said Monday that the United States is still ruling out possible military action in Crimea. Geoffrey Pyatt said any diplomatic solution must address Moscow’s interests in the strategically important peninsula. Pyatt reiterated that the U.S. will not recognize the results of the "so-called" referendum in Crimea set for March 16.
The White House said Monday that President Barack Obama began a new round of diplomatic consultations on Ukraine with phone calls to Chinese President Xi Jinping, Spain's Prime Minister Mariano Rajoy and Kazakh President Nursultan Nazarbayev.
Despite international objections, the chief of Crimea's election commission said Monday that he is moving ahead with preparations for next Sunday's unification referendum. Myhkailo Malyshev said all registered Crimean voters are eligible to vote.
Putin has defended the separatist drive in Crimea as consistent with international law, and a regional leader said Ukrainian troops remaining there should leave the territory unless they renounce their loyalty to Kyiv.
Crimea has invited observers from the Organization for Security and Cooperation in Europe (OSCE) to monitor the referendum, according to Russia's RIA news agency.
On Saturday, an unarmed observer mission from the same Vienna-based group tried to cross into Crimea but had to turn back after warning shots were fired.
Ukrainian interim prime minister Arseniy Yatsenyuk vowed Sunday not to give up "a single centimeter" of territory.
Yatsenyuk is scheduled to meet Obama on Wednesday to discuss the standoff over Crimea, a strategic peninsula in southern Ukraine with a Russian-speaking majority. A White House statement said the visit will highlight the United State's strong support of the people of Ukraine, and will include talks on economic aid and preparations for May elections there.
Meanwhile, Ukraine's defense department said armed men in uniforms surrounded and seized a Crimean naval base at Chernomorskoye, and a military hospital in Simferopol. The New York Times newspaper reported police interrupted an interview with a local man in Chernomorskoye, threatening its reporters and seizing their notes.
Reporters Without Borders said Monday that unidentified gunmen seized two female Ukrainian journalists in Crimea. The group warned that attacks on the media were attempts to turn the region into a "black hole for news."
As demonstrators staged rival rallies in Crimea and throughout Ukraine, street violence flared in Sevastopol when pro-Russian activists and Cossacks attacked a group of Ukrainians.
Despite the reports, Russia has accused far-right activists in Ukraine and the pro-Western Kyiv government of creating "chaos." A statement released Monday from the Russian foreign ministry, which singled out the far-right Ukrainian group "Right Sector," also accused Western governments of ignoring the violence.
Russia denies it has troops on the peninsula beyond those regularly stationed with its Sevastopol-based Black Sea fleet. Ukraine's much smaller navy is also based in the Crimean port city. Witnesses say although the soldiers have no insignia identifying them, they are clearly Russian.
Some information in this report was provided by Reuters news agency.