Saudi Arabia has expressed "great willingness" to boost oil production to ensure potential new US sanctions on Iran don't disrupt global petroleum markets, a key US senator said Tuesday.

Republican Senator Mark Kirk, co-author of a bill aimed at cutting off Iran's central bank from the world financial system, was addressing worries that his legislation could inadvertently send oil prices higher, lining Tehran's pockets.

"I've had detailed conversations with Saudi Arabia's ambassador to the United States, who described a great willingness by Saudi Arabia to increase production," to remedy that potential issue, Kirk told reporters.

The senator said he and Democratic Senator Robert Menendez met with aides to President Barack Obama earlier in the day to make the case that the administration should drop its opposition to the sanctions bill.

"I don't think that they were swayed," according to Kirk, who said that the two lawmakers had stressed that the legislation gives the administration "considerable flexibility in handling" the imposition of sanctions.

"There are several months before action by the administration, so it gives time for diplomacy to work, it gives time for markets to adjust, and most importantly it gives time for the Saudis to increase production," he said.

"Unless we take decisive action on sanctioning, I think what Iran is doing actually destabilizes oil markets in a more significant way," said Kirk, who cited "the takeover of the British embassy" and new reports seen as backing Western charges that Tehran seeks nuclear weapons.

"The attainment of a nuclear weapon by Iran would destabilize world markets far more than any action of the senate," he said. "Time is not on our side."