Pro-Russian activists follow special U.N. envoy Robert Serry in front of the airport in Simferopol, Ukraine, Wednesday, March 5, 2014. The special U.N. envoy 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. (AP Photo/Darko Vojinovic)

This image taken from AP video shows UN Special Envoy to Ukraine, Robert Serry, answering questions as he leaves the naval headquarters in Simferopol, Ukraine, 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)

Ukrainian ex-Minister of Transport and Communication, Mykola Rudkovskiy, talks to media in front of the business class lounge of the airport in Simferopol, Ukraine, Wednesday, March 5, 2014. Special U.N. envoy, Robert Serry, 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. (AP Photo/Darko Vojinovic)

Ukrainian ex-Minister of Transport and Communication, Mykola Rudkovskiy, talks to media in front of the business class lounge of the airport in Simferopol, Ukraine, Wednesday, March 5, 2014. Special U.N. envoy, Robert Serry, 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. (AP Photo/Darko Vojinovic)

This image taken from AP video shows UN Special Envoy to Ukraine, Robert Serry, being asked questions by a journalist as he leaves a cafe in Simferopol, Ukraine, Wednesday, March 5, 2014, before entering a van which took him to Simferopol airport. 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)

A Pro-Russian activist coming out of the business class lounge of the airport in Simferopol, Ukraine, Wednesday, March 5, 2014. Special U.N. envoy, Robert Serry, 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. (AP Photo/Darko Vojinovic)

This image taken from AP video shows UN Special Envoy to Ukraine, Robert Serry, shaking hands with a woman as he leaves a cafe in Simferopol, Ukraine, Wednesday, March 5, 2014, before entering a van which took him to Simferopol airport. 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)

A Ukrainian police officer gives instructions in front of the business class lounge of the airport in Simferopol, Ukraine, Wednesday, March 5, 2014. Special U.N. envoy, Robert Serry, 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. (AP Photo/Darko Vojinovic)

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)

This image taken from AP video shows van outside a cafe in Simferopol, Ukraine, which had UN Special Envoy to Ukraine, Robert Serry 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)

This image taken from AP video shows UN Special Envoy to Ukraine, Robert Serry inside a cafe in Simferopol, Ukraine, as men in camouflage outfits stood outside 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)

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)