Simferopol, Ukraine (AP) - Situated on road to Simferopol, the Crimean port where Russia maintains its naval base, 12 military trucks carrying troops and a Tiger vehicle armed with a machine gun and also two ambulances were sighted on the premises.

According to the Ukrainian Defense Ministry the Russian military forces retrieved weapons from two military posts. The Russian troops forced personnel on site to side with the "legitimate" leaders of the Crimean Peninsula.

Russian President Vladimir Putin has rejected calls from the West to pull back his forces, insisting that Russia has a right to protect its interests and the Russian-speaking population in Crimea and elsewhere in Ukraine.

Ukraines ambassador to the United Nations asked for an emergency session of the Security Council "to do everything possbile now" to stop Russia's "aggression".

But the UN seems reluctant to take a move, as Russia has veto power to block the council from sanctioning Moscow.

UN Secretary General Ban Ki-moon made a phone call to Russian President Vladimir Putin asking him to "engage in direct dialogue with authorities" in Kiev.

Putin showed his frustration against the threat of violence against Russian speakers in eastern Ukraine and Crimea, saying that they "will take necessary measures in the framework of international law".

The US ambassador to the UN Samantha Power called the situation in Ukraine "as dangerous as it is destabilizing," and asked for the "Russian military intervention in Ukraine to end."

Ban Ki-moon said on Saturday that he is "gravely concerned about the deterioration of the situation" in Ukraine and called for "full respect for and preservation of the independence, sovereignty and territorial integrity" of the country.