Flanked by four of his top generals at the Pentagon, President Barack Obama has defended his strategy on defeating Isis saying the United States was leading the effort to “squeeze its heart” in its stronghold in Syria and Iraq and stymie its ability to “pump its terror to the rest of the world”.

Anxious to deflect criticism that the US has been stumbling in its response to the Isis threat and is equally ill-prepared to prevent any new terror attacks at home where the horror of San Bernardino is still strongly felt, Mr Obama insisted that the US and its allies was hitting the group “harder than ever”.

After ticking off a roster of Isis figures killed recently by coalition strikes, including Mohammed Emwazi, the London-raised Isis execution known as Jihadi John, Mr Obama said there was more of the same to come. The leaders of Isis, “cannot hide and our message to them is simple: you are next,” he declared. Also by his side at the Pentagon briefing room was Vice President Joe Biden.

“We are hitting Isil harder than ever,” Mr Obama insisted, using an alternative acronym for Isis. He noted a new intensity of airstrikes in part thanks to the participation of Britain, which is now hitting targets in Syria as well as in Iraq, and also France, Italy and Australia. “Coalition aircraft, our fighters, bombers, and drones have been increasing the pace of airstrikes, nearly 9,000 as of today,” he said.

The rare visit by the president at the Pentagon came as the White House tries to push back against the perception that Mr Obama has been slow to respond to Isis, a sense that deepened after his Oval Office address delivered in the wake of the San Bernardino mass shooting that was widely panned.

Once again, he offered nothing new in terms of overall strategy, but said he was dispatching the Secretary of Defence, Ashton Carter, to the region on a mission to rally more countries there to contribute to the campaign against Isis. He is expected to stop first in Iraq, where efforts to retake the city of Ramadi have been delayed. He will also go to Turkey, officials said.

There has meanwhile been little progress on resolving differences between the US and Russia on strategy in Syria. Even as US Secretary of State John Kerry was flying to Moscow tonight for talks with his counterpart, Sergei Lavrov, and President Vladimir Putin, the Russian foreign ministry issued a press release complaining that the US was “dividing terrorists into good and bad ones” in Syria.

The comments indicated a frosty welcome for Mr Kerry. The same statement asserted that the US was refusing to enter into a “full-fledged coordination” with Russian forces in Syria. For its part, the US still believes that Russia is using air strikes to bolster President Bashar al-Assad more than attack Isis.

A full 29 per cent of Americans fear they may be the victims of a terror attack one day, according to a new MSNBC poll. Meanwhile 32 per cent said they feared being caught in a mass shooting. Today is the third anniversary of the Newtown, Connecticut, elementary school shooting. Meanwhile the twin anxieties about terror attacks and shootings became one in the form of the massacre in San Bernardino, carried out by a Muslim married couple with an allegiance to extreme Islam.

Mr Obama’s handling of the Isis threat as well as the new spectre of terror attacks at home has rushed to the top of the presidential scramble and is likely to dominate at a Republican debate in Las Vegas tomorrow night.