The US Treasury has imposed sanctions on Antal Rogan, one of the most powerful men in Hungarian Prime Minister Viktor Orban's Fidesz government and the minister in charge of his cabinet office.

On Tuesday, a top Hungarian government official and adviser to Prime Minister Viktor Orban was sanctioned for alleged corrupt activity by the United States, according to the U.S. Department of State.

The United States imposed sanctions on a senior member of the Hungarian government for alleged corruption, the U.S. Treasury said on Tuesday, a move Budapest said it would challenge when President-elect Donald Trump takes power.

The US has placed Viktor Orbán’s chief of staff under sanctions for alleged corruption, the highest-ranking Hungarian official to be blacklisted since the fall of Communism. Antal Rogán, a longtime ally of the Hungarian prime minister overseeing state-owned media and part of the intelligence services,