Credit: Sergei Grits/AP Photo

KIEV, Ukraine - For the second straight day, European monitors have been barred from entering the Crimean peninsula by armed and masked pro-Russian forces.

More than forty military and civilian monitors from the Organization for the Security and Co-operation in Europe tried to enter Crimea, but said they would go back to the Ukrainian town of Kherson to figure out their next move.

"We are just trying to go through here as guests of the Ukrainian government under an OSCE mandate," an observer told Agence France-Presse. "We're going to try and negotiate with these people here."

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The OSCE has described the mood in Crimea - where troops believed to be Russian have surrounded Ukrainian military bases demanding their surrender - as "calm, but very tense."

"It is a miracle that there has been no blood-shed yet," OSCE envoy Tim Guldimann told reporters yesterday.

Access for international monitors was one of the main points raised by President Barack Obama last night during a call with Russian President Vladimir Putin.

Both the Kremlin and White House issued readouts of the hour-long call - the second between the two presidents in less than a week.

But the two statements had little in common, apart from agreeing that Secretary of State John Kerry and Foreign Minister Sergei Lavrov should continue talking.

As the diplomatic stalemate continues, a delegation of lawmakers from Crimea arrived in Moscow today following the announcement that a referendum will be held on March 16 to determine the region's status as part of Russia or Ukraine.

"Without a doubt, the Crimean parliament, as a legitimate authority, has that right," Valentina Matviyenko, the speaker of Russia's upper house, said. "The sovereign right of the people to determine their future."