Crimea's new leader: 11,000 pro-Russian troops have Ukraine's peninsula under full control

This image taken from AP video shows a group of unidentified men in military fatigues outside a cafe in Simferopol, Ukraine who appear to be stopping UN Special Envoy to Ukraine, Robert Serry from leaving as he makes a call on his mobile phone inside, Wednesday, March 5, 2014. The special U.N. envoy who is visiting Crimea was threatened by 10 to 15 armed men on Wednesday and ordered to leave the region, where Ukraine and Russia are locked in a tense standoff, U.N. officials said. Later, an Associated Press reporter found Robert Serry in the business class lounge of the Simferopol airport on Wednesday evening. "I'm safe. My visit was interrupted for reasons that I cannot understand," the Dutch diplomat said in a statement to AP. He said nothing more. (AP Photo/AP video) (The Associated Press)

This image taken from AP video shows Robert Serry sat in a cafe in Simferopol, Ukraine, as he makes a call on his mobile phone, Wednesday, March 5, 2014 as men in famouflage outfits stood outside. The special U.N. envoy who is visiting Crimea was threatened by 10 to 15 armed men on Wednesday and ordered to leave the region, where Ukraine and Russia are locked in a tense standoff, U.N. officials said. Later, an Associated Press reporter found Robert Serry in the business class lounge of the Simferopol airport on Wednesday evening. "I'm safe. My visit was interrupted for reasons that I cannot understand," the Dutch diplomat said in a statement to AP. He said nothing more. (AP Photo/AP video) (The Associated Press)

The new leader of Ukraine's Crimea region says pro-Russian forces control all access to the strategic peninsula and have blockaded all Ukrainian military bases that have not yet surrendered.

Sergei Aksyonov says riot police and security forces have been joined by 11,000 self-defense troops. All or most of these troops are believed to be Russian, even though the Russian president and defense minister have denied sending in troops.

The West has joined the new Ukrainian leadership in demanding that Russia pull its forces from Crimea, but little progress was reported after a flurry of diplomatic activity Wednesday.

A U.N. special envoy sent to Crimea was threatened by 10 to 15 armed men, a U.N. official said.

Speaking late Wednesday, Aksyonov said his government is in regular contact with Russian officials.