WASHINGTON - The top congressional Republican laid into President Barack Obama Thursday, accusing him of taking a “nap” on Iraq, while a lawmaker called for US air strikes to repel Islamist rebels advancing on Baghdad.

With jihadists capturing several large Iraqi cities, forcing hundreds of thousands of residents to flee, and threatening Baghdad, hawkish Senator John McCain called for “drastic measures” to reverse the tide and said Obama should sack his national security team for failed policies in the Middle East.

“Get a new national security team in place. You have been ill-served,” he told Obama in a speech on the Senate floor.

House Speaker John Boehner angrily snapped that the Obama administration has seen the pressure on Iraq’s government building for over a year but did little to help authorities there counter the insurgents.

“Now they’ve taken control of Mosul, they’re 100 miles (160 kilometers) from Baghdad,” Boehner told reporters. “And what’s the president doing? Taking a nap.”

Senate Republican Lindsey Graham, who often joins McCain in his condemnation of Obama foreign policy, bluntly warned that a jihadist takeover in Iraq and neighboring Syria would create a “hell on earth.” And while US boots on the ground is not an option at present, “I think American airpower is the only hope to change the battlefield equation in Iraq,” Graham said.

“The Iraqi army is in shambles, and without some kind of intervention, Baghdad is definitely in jeopardy.”

McCain and Graham urged Obama to sit down with his generals and consult with retired personnel who oversaw Iraqi operations, including former CIA chief General David Petraeus, to map out a change of course. “I have never been more worried about another 9/11 than I am right now,” Graham warned.

He also said Obama erred in not leaving residual forces once the last US troops pulled out in 2011. “Ten or 15,000 strategically placed US soldiers would have held this together,” Graham said.

Former secretary of state Hillary Clinton came to the president’s defense Thursday, saying the deadline on US troops leaving Iraq “was set by the prior administration.”

She also pointed to Iraqi Prime Minister Nuri al-Maliki’s failure to approve a status of forces agreement with Washington under which US troops could remain in country.

“So the decision was made, in effect. There could not be American troops left without such an agreement,” Clinton said at the Council of Foreign Relations.

Meanwhile, President Hassan Rouhani warned on Thursday that Iran would combat the “violence and terrorism” of extremists who have launched an anti-government offensive in neighbouring Iraq.

“This is an extremist, terrorist group that is acting savagely,” Rouhani said live on state television.

“For our part, as the government of the Islamic Republic of Iran ... we will combat violence, extremism and terrorism in the region and the world,” said an agitated Rouhani.

The president spoke even as the heavily armed militant group on Thursday seized a string of towns near Baghdad after a lightning offensive that began in Nineveh province late on Monday.

Syrian state media on Thursday accused Saudi Arabia and the West of complicity with the jihadist Islamic State of Iraq and the Levant that has captured swathes of Iraqi territory.

Echoing claims often made by the regime and its supporters, state media said Saudi and other allies of the Syrian opposition were funding and arming jihadist groups like ISIL.

“Terrorism is spreading in front of the eyes of the western world... and alongside it are the fingers of Saudi Arabia, providing money and arms,” the Al-Thawra daily wrote.

“In the events in Iraq and the escalating terrorist campaign, no Western country is unaware of the role Saudi is playing in supporting terrorism and funding and arming different fronts and battles, both inside and outside Iraq and Syria,”

The editorial also accused Qatar and Turkey of playing similar roles backing extremists “according to US demands or Israeli desires.”

“The emergence of these organisations is not the result of a vacuum but rather long and clear support for terrorism... which the Gulf has dedicated its finances to expanding,” it said.

Such actions were taken “with Western knowledge and in most cases clear and explicit orders,” the newspaper continued.

Syria’s government deems all those seeking to oust President Bashar al-Assad “terrorists” and has drawn no distinction between jihadists like ISIL and other rebel groups, despite ongoing fighting between the armed opposition in rebel territory.

It accuses Gulf nations including Saudi and Qatar of working with the West and arch-enemy Israel to fund “terrorists” seeking to overthrow the regime.

The newspaper’s comments came after ISIL, a former Al-Qaeda affiliate in Iraq that has expanded into Syria and cut ties with its onetime sponsor, seized the Iraqi towns of Mosul and Tikrit.

Its shock advance has prompted sharp concern, and comes despite the group’s ongoing battles against the regime and other rebel groups in Syria.

Some in Syria’s armed opposition welcomed ISIL to the battle when it first emerged there in 2013.

But its brutal tactics and abuses against civilians and rival rebels prompted a backlash that escalated into full-fledged battle between ISIL and a coalition of moderate and rebels backed by Al-Qaeda affiliate Al-Nusra Front. Though it grew from Al-Qaeda’s Iraq affiliate, the group’s leader has disavowed ISIL and urged it to return to Iraq.