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.

BUDAPEST, Hungary (AP) — A senior Hungarian government official close to Prime Minister Viktor Orbán was hit Tuesday with U.S. sanctions for his alleged involvement in corruption in Hungary, a rare step against a sitting official in an allied country.

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,

The United States announced sanctions against the head of Hungarian Prime Minister Viktor Orban's cabinet on Tuesday for his alleged involvement in corruption."This systemic corruption Antal Rogan represents is affecting Hungary's decision-making on issues that impact the security of the United States of America and our allies,

The U.S. administration announced on Tuesday that it would sanction Antal Rogan, the head of Hungarian Prime Minister Viktor Orban's cabinet, for corruption. According to the State Department, the case of the prime minister's close associate exemplifies "state capture by oligarchs and undemocratic actors.