The office of U.S. Attorney for the Southern District of New York Geoffrey Berman announced the federal government’s seizure of a North Korean coal freighter Thursday, in a move Berman called a statement the first-ever seizure of a North Korean cargo vessel for violating international sanctions.

The announcement comes shortly after renewed tension with the U.S. and North Korean governments, following a series of missile launches by the latter. The timing of the announcement by the Manhattan U.S. attorney’s office raised questions: The vessel was seized more than a year ago by Indonesian officials.