(Reuters) -- U.S. lawmakers are considering a bid to force President Barack Obama's administration to blacklist Iran's President Mahmoud Ahmadinejad and the country's supreme leader, Ayatollah Ali Khamenei, in an effort to thwart Tehran's nuclear capabilities, a congressional aide said on Wednesday.

The new measure under consideration would designate the Iranian leaders as human rights abusers and freeze whatever assets they have in the United States as well as deny them visas needed to enter the country, the aide said.

The Senate Banking Committee could decide as soon as Thursday on whether to include the provision in a broad package of sanctions aimed at curtailing Iran's access to oil revenue, which the West says is being used to develop nuclear weapons.

Iran insists its nuclear program is aimed at developing technologies for peaceful purposes.

The fresh penalties would build on a new oil embargo by Europe and sanctions by the United States that seek to shut down Iran's main clearinghouse for oil revenues, the Iranian central bank.

So far the Obama administration has been grappling with how to implement the law, which bars countries and companies from the U.S. financial system if they fail to significantly reduce their volume of crude oil purchases.

The new measures being considered in Congress include requiring the administration to identify officials, affiliates and agents of Iran's revolutionary Guard within three months and impose sanctions on them.

(Reporting By Rachelle Younglai; editing by Todd Eastham)

Nuclear weapons Crude oil Human rights Barack obama