As the Parliament in Crimea is set to vote on regional secession, the Obama administration has issued sanctions including travel bans and visa revocations:

The sanctions Mr. Obama approved Thursday imposed visa bans on officials and other individuals deemed responsible for undermining Ukrainian sovereignty and territorial integrity. The administration would not disclose the names or number of people penalized, but a senior official said privately that it would affect just under a dozen people, mostly Russians but some Ukrainians.
Among those targeted were political figures, policy advisers, security officials and military officers who played a direct role in the Crimean crisis, the official said. Any of them seeking to travel to the United States would be barred, and a few who currently hold American visas will have them revoked.

Republican Congresswoman Ileana Ros-Lehtinen said that while these sanctions were a step in the right direction "we must name and shame these persons[.]" This comes after a report in February that the State Department had imposed a visa ban on twenty senior Ukrainian officials, whom had allegedly played a role in the violent crackdown of protestors by the government of ousted President Yanukovych. UK Prime Minister David Cameron has also backed travel bans for senior Russian politicians, and European Union member states in coordination with the US, Switzerland, Turkey, Japan, and Canada have reportedly agreed on travel restrictions as well.