DHAKA: Russian President Vladimir Putin appeared Saturday to dismiss warnings from world leaders to avoid military intervention in Ukraine`s Crimean peninsula, even amid growing evidence that pro-Russian forces were already in control of the region.

The rhetoric escalated Saturday night, with U.S. Secretary of State John Kerry condemning what he called "the Russian Federation`s invasion and occupation of Ukrainian territory" despite a statement by Russia Prime Minister Dmitry Medvedev that no decision had been made on whether Moscow would dispatch forces, reports CNN.

Russia has not confirmed it deployed thousands of troops to the region following reports that armed, Russian-speaking forces wearing military uniforms without insignia patrolled key infrastructure sites.

It was the latest in fast-moving developments that saw Russia`s Parliament sign off on Putin`s request to send military forces into Ukraine, raising the stakes in the escalating game of brinksmanship.

The move prompted world diplomats to call for a de-escalation of tensions that have put the two neighbors on a possible path to war and roiled relations between Russia and the United States.

In what appeared to be an illustration of the growing schism between the two world powers, U.S. President Barack Obama and Putin spoke for 90 minutes -- with each expressing their concern over the mounting crisis, according to separate statements released by their respective governments.

According to the Kremlin, Putin told Obama that Russia reserves the right to defend its interests in the Crimea region and the Russian-speaking people who live there.

"President Obama made clear that Russia`s continued violation of Ukraine`s sovereignty and territorial integrity would negatively impact Russia`s standing in the international community," according to a statement released by the White House.

Ukraine, a nation of 45 million people sandwiched between Europe and Russia`s southwestern border, has been plunged into chaos since the ouster a week ago of President Viktor Yanukovych following bloody street protests that left dozens dead and hundreds wounded.

Ukraine has faced a deepening schism, with those in the west generally supporting the interim government and its European Union tilt, while many in the east preferring a Ukraine where Russia casts a long shadow.

Nowhere is that feeling more intense than in Crimea, the last big bastion of opposition to the new political leadership. And Ukraine suspects Russia of fomenting tension in the autonomous region that might escalate into a bid for separation by its Russian majority.

Ukraine acting President Oleksandr Turchynov took to the airwaves late Saturday to warn any Russian military intervention would lead to war.

Prime Minister Arseniy Yatsenyuk said his country was ready to mobilize its forces to protect strategic locations, including nuclear power plants.

BDST: 0836  HRS, MAR 01, 2014