Washington: Republicans critical of US-Iran nuclear talks contend President Barack Obama is so keen for a deal that he is ignoring Tehran’s moves to expand its influence across the Middle East.

GOP hawks maintain that Obama wants so much to burnish his legacy by negotiating an agreement to restrain Iran from becoming a nuclear-armed state that he is not pushing back against Iranian activities in Iraq, Yemen, Syria, Lebanon and Bahrain.

Secretary of State John Kerry has push back against lawmakers, including some who insist that the nuclear negotiations have hamstrung US policy decisions in the region.

“Yes, Iran’s influence has spread at this moment and we are deeply concerned about it,” Kerry said at one congressional hearing. “But if you’re concerned about it now, think of what happens... if they had a nuclear weapon.”

Republicans point to the activities of Iran, the dominant Shiite force in the Middle East.

“The Iranians are now in Sana’a. They’re in Baghdad and Beirut and Damascus and meanwhile this president and secretary of state pursue the mirage of a nuclear agreement,” Senator John McCain, the chairman of the Armed Services Committee, said in a recent speech.

Banging the podium, McCain lamented how the Iranian-backed militias are fighting the Daesh group in Tikrit, the Sunni stronghold and hometown of former Iraqi leader Saddam Hussain. Directing the offensive is Iranian General Qassem Sulaimani, commander of the powerful Revolutionary Guard’s Quds Force. The overt Iranian role and the prominence of militias in the campaign have raised fears of possible sectarian cleansing should Tikrit fall.

“Sulaimani is the same guy that sent copper-tipped IEDs [improvised explosive devices] into Iraq, which killed hundreds of American soldiers and Marines,” McCain said. “That is not only unbelievable. It is totally unacceptable.”

Senator Lindsey Graham, complained that the administration remains silent about the havoc Iran is creating on the ground.

“If I were president, I would tell the Iranians we’re not going to talk to you any more about your nuclear ambitions until you stop destabilising the region and invading your neighbours,” said Graham, who is weighing a White House bid.

Among the Democrats countering the Republican refrain, Senator Tim Kaine, says he shares the concern about Iran’s involvement but “this is not about turning Iran from an enemy into a friend. This is whether an enemy has a nuclear weapon or doesn’t. The administration is very realistic. If there is a good nuclear deal, we still have to confront the adventurism of Iran beyond its borders.”

In defence of the administration, Kerry says the US cooperated with Israel in tracking and interdicting a ship carrying Iranian rockets going to Palestinian fighters. In December, Kerry said the US helped the Bahrain Coast Guard interdict a ship carrying weapons of Iranian origin bound for its proxy groups.

Late last year, Obama designated the six-member Gulf Cooperation Council as eligible for foreign military sales, meaning they can purchase weapons as an entity in order to lay the groundwork for them to deal with challenges that they feel from Iran.

At one hearing, Senator Thad Cochran kept at it with Kerry.

“Do you agree with me that the Al Houthis in Yemen couldn’t last 15 minutes without Iranian support?” asked Cochran.

“They’ll probably last longer than 15 minutes, but obviously Iranian support is critical,” Kerry answered.

“Do you agree with me that Al Assad is a puppet of the Iranian regime? Cochran asked.

“Pretty much,” Kerry said.

“Do you agree with me that Hezbollah is a subcontractor of the Iranian regime?” Cochran asked.

“Totally,” Kerry answered. He then insisted the administration is not looking the other way.

“We’re not oblivious to these tentacles,” he said.