Former vice-president Dick Cheney met behind closed doors with Republican members of Congress on Tuesday to urge them to adopt a more muscular military posture in the Middle East.



The private meeting came as leading Republican hawks are clamouring for a ramped-up confrontation with the Islamic State (Isis) militant group, with some openly discussing the redeployment of ground troops in Iraq.



Cheney did not address the specifics of any military involvement in the Middle East, according to several people present at the meeting, which took place in the Capitol Hill Club and was open to all House Republicans.



But he decried what Republicans perceive to be president Barack Obama’s “weakness”, said legislators should boost military spending and provided a neo-conservative analysis of the conflict embroiling the Middle East.



One source who was in the room told the Guardian that Cheney’s remarks were “tantamount to a pep talk” before Obama’s address to the nation on Wednesday, in which the president will unveil the administration’s plan for tackling Isis, which has taken over large swathes of Iraq and Syria.



“There was a lot of rapt attention in the room,” said Illinois representative Adam Kinzinger. “It wasn’t anything berating necessarily to Republicans. Just strong on the fact that we have to stand together.”



Kinzinger added: “It was a great message, something we needed to hear, and hopefully it sticks with a lot of my colleagues who’ve had this creep toward isolationism. Hopefully this is an awakening that we have to be very strong.”



Another Republican congressman, John Fleming of Louisiana, said Cheney’s remarks had been “extremely important” for the party.

Dick Cheney in 2013. Photograph: Miranda Grubbs/AP

“He basically said that President Obama has actually done things that have supported the Muslim Brotherhood. But on the other hand the Muslim Brotherhood is really the beginnings of all the Islamist groups that we’re now dealing with; Hamas, Isis – all of those groups.”

Referring to Obama’s plan to withdraw troops from Afghanistan by the end of 2016, Fleming added: “He said that we’re doing the same thing that we did in Afghanistan that we did in Iraq, and we’re going to get the same terrible results. We need to immediately to an about face.”

Obama, who will meet with both Republican and Democratic congressional leaders later on Tuesday, is determined to keep to his timetable for troop withdrawal in Afghanistan and has said the combat troops he pulled out of Iraq in 2011 will not return.



However the Pentagon and the president’s national security team are considering broadening the air campaign that has so far targeted Isis in Iraq into neighbouring Syria, as part of a concerted, internationally-backed effort to “degrade and destroy” the group.



White House officials want buy in from both Congress and key regional players in the Middle East before intensifying the US attack on Isis, although they believe the administration has the legal authority to step up military action independently of lawmakers.



Legislators in both parties are divided over whether Congress should have a formal vote over Obama’s policy on Isis, with many wary of being drawn into a potentially controversial issue less than two months before November’s midterm elections.



Following the meeting with Cheney, the Republican speaker of the House, John Boehner, declined to answer whether he would support the use of ground troops in Iraq – or to say whether he would hold a vote on Obama’s foreign policy.

But asked whether the US should take the fight against Iraq into Syria, he replied: “I think we need to be going after the terrorist threat wherever it is.”