According to a notice posted this week on the State Department’s adoption website (www.adoption.state.gov):

“We have received no official notification that adoptions of Russian orphans by Americans have been suspended, but it is clear the recent controversy has slowed down adoptions in some parts of the country. 

“Volcanic ash prevented the U.S. delegation from traveling to Moscow over the April 17^thweekend.The talks in Moscow between U.S. and Russian officials are now rescheduled for April 29 and 30.  The United States plans to emphasize the importance of this issue, and will discuss our mutual concerns about how to better protect the welfare and rights of children and all parties involved in intercountry adoptions.” 

The rest of the notice is available here.