Iran's foreign ministry said on Friday that the United States had no option but to strike a nuclear deal with Tehran, after a Republican bid to block the agreement failed.

US President Barack Obama hailed as a "victory for diplomacy" Thursday's Senate vote during which a Democratic minority in the US Senate staved off the bid to sink the nuclear deal.

But foreign ministry spokeswoman Marzieh Afkham played down his comments saying it was "explicitly paradoxical," the official IRNA news agency reported.

She said the United States "was forced into negotiating" the deal with Iran due do the "failure of the US policy of sanctions and threats", the agency reported.

The July deal between Iran and six world powers -- China, Britain, France, Germany, Russia and the United States -- limits Tehran's nuclear programme in exchange for lifting painful economic sanctions.

"The US president, fruitlessly, tries to claim the results of the nuclear negotiations, but the truth is ... the US had no alternative but giving up its excessive demands," Afkham said.

"The world would definitely be safer when the US administration ends its authoritarian behaviour and prevents the destabilising and warmongering actions by its allies," she added.

She was taking a jibe at Obama who also said that the Senate vote was a "victory... for the safety and security of the world".

Republicans complain the deal does not do away with Iran's nuclear programme, which Tehran insists is for peaceful purposes.

They say it fails to provide for spot inspections of nuclear sites or force Iran to end support for militant groups like the Palestinian Islamist movement Hamas.

Iran accuses the US of interfering in the affairs of its regional allies, Iraq and Syria, and denounces American support for the Saudi-led coalition strikes against Shiite Yemeni rebels.

North Dakota senator worried Iran will cheat
Washington (UPI) Sep 11, 2015 - Iran stands to get a $100 billion economic lift in the form of sanctions relief, a senator from the oil-rich state of North Dakota said.

Democrats in the U.S. Senate handed President Barack Obama a victory by blocking a Republican measure to shoot down the July nuclear agreement reached between Iran, the five permanent members of the U.N. Security Council, plus Germany.

U.S. Sen. John Hoeven, R-N.D., said he had reservations about a deal he said would lift sanctions but fall short of putting a complete halt to Iran's nuclear research program.

"Based on Iran's track record, it is very likely that they will cheat on the agreement after receiving more than $100 billion to strengthen their economy and military," he said in a statement. "But ironically, even without cheating, this agreement gives Iran the ability to achieve its nuclear ambitions."

Hoeven, whose state is the No. 2 oil producer in the United States, is among the Republican leaders pressing for an end to a 1970s ban on U.S. crude oil exports. With North Dakota's shale oil behind much of the U.S. production momentum, supporters of lifting the ban say U.S. oil could be used as a strategic tool overseas.

By a voice vote, the Republican-led House Subcommittee on Energy and Power advanced legislation that would lift the ban on crude oil exports.

In a letter of support for the bill, the National Foreign Trade Council said U.S. crude oil exports would have "constructive strategic consequences" for national security. George Baker, executive director of the Producers for American Crude Oil Exports, said U.S. crude oil could be a "stable alternative to Iranian crude oil."

President Obama countered, however, that moving forward with what his administration considers to be a diplomatic victory that in turn protects U.S. national security interests.

"Going forward, we will turn to the critical work of implementing and verifying this deal so that Iran cannot pursue a nuclear weapon, while pursuing a foreign policy that leaves our country - and the world - a safer place," he said.