The United States on Friday imposed sanctions on head of the Free Patriotic Movement MP Gebran Bassil, accusing him of corruption, the Treasury Department said.
The U.S. move against Bassil, a former foreign minister, was the latest against political figures in Lebanon, a country struggling under a series of political and economic crises.
In recent months Washington has placed sanctions on several officials linked to Hezbollah, the armed Iran-backed Shi'ite group that has become an overarching power in the country.
The Treasury Department said Bassil was at the "forefront of corruption in Lebanon."
"The systemic corruption in Lebanon’s political system exemplified by Bassil has helped to erode the foundation of an effective government that serves the Lebanese people," Treasury Secretary Steven Mnuchin said in a statement.
The latest move could complicate efforts by Prime Minister-designate Saad Hariri, who was named last month, to form a government.
He has been trying to navigate Lebanon's sectarian politics to name a cabinet to bring in reforms needed to tackle the country's worst crisis since its 1975-1990 civil war, including banking paralysis, a currency crash and spreading poverty.