By Humeyra Pamuk and Matt Spetalnick
WASHINGTON (Reuters) - The United States imposed sanctions on Friday on Gebran Bassil, the leader of Lebanon's biggest Christian political bloc and son-in-law of President Michel Aoun, accusing him of corruption and ties to Hezbollah.
Bassil heads the Free Patriotic Movement (FPM), founded by Aoun, and has served as minister of telecoms, of energy and water and of foreign affairs.
The target of protests that erupted last year against a political class accused of pillaging the state, Bassil said in a Twitter post that sanctions did not scare him and that he had not been "tempted" by promises.
The sanctions could complicate efforts by Prime Minister-designate Saad al-Hariri to navigate Lebanon's sectarian politics and assemble a cabinet to tackle a financial meltdown, the country's worst crisis since its 1975-1990 civil war.
A source familiar with the process said the move was likely to harden the FPM's stance in negotiations on a new government needed to enact reforms demanded by foreign donors to tackle endemic corruption, waste and mismanagement to unlock aid.
In recent months, the United States has also placed sanctions on several officials linked to Hezbollah, the armed Iran-backed Shi'ite movement that has become Lebanon's most powerful political force, and which Washington considers a terrorist group.
Hezbollah condemned the U.S. move as purely political and "a blatant and gross interference."
"This decision specifically aims to force a big Lebanese political team to submit to American conditions and dictates on Lebanon," it said in a statement.
The FPM has a political alliance with Hezbollah and Bassil has defended the group as vital to the defense of Lebanon.
The Treasury Department said Bassil was at the "forefront of corruption in Lebanon" where successive governments have failed to reduce mounting sovereign debt or address failing infrastructure and the loss-making power sector that cost state coffers billions of dollars while power cuts persisted.
"Through his corrupt activities, Bassil has also undermined good governance and contributed to the prevailing system of corruption and political patronage that plagues Lebanon, which has aided and abetted Hizballah’s (Hezbollah) destabilizing activities," U.S. Secretary of State Mike Pompeo said in a statement.
A senior U.S. official said Bassil's support for Hezbollah was "every bit of the motivation" for targeting him for sanctions.
Bassil was sanctioned under the Global Magnitsky Human Rights Accountability Act, which targets human rights abuses and corruption around the world. It calls for a freeze on any U.S. assets and prohibits Americans from doing business with him.
The State Department also imposed a ban on Bassil's travel to the United States.
A senior U.S. official said the sanctions announcement was "not intended to impact a government formation process" in Lebanon. The official also denied any connection between the announcement and this week's U.S. elections, saying such sanctions packages take months to prepare.
(Reporting by Humeyra Pamuk and Matt Spetalnick ; Additional reporting by Ghaida Ghantous and Samia Nakhoul; Editing by William Maclean, Peter Graff, Alison Williams and Tom Brown)