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 placed sanctions on Hungarian Prime Minister Viktor Orban’s influential cabinet chief for his alleged role in corruption, just days before Orban’s ally Donald Trump takes over in the White House.

Antal Rogan is the first high-ranking Hungarian official sanctioned by the U.S. under the Magnitsky Act, which targets individuals involved in serious human rights abuses and corruption.

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