Britain will invade other countries if the UK’s national interests are threatened or an ally asks for help, defence secretary Sir Michael Fallon has said.

However the UK will “not simply embark on foreign adventures for the sake of it”, Sir Michael said.

Sir Michael told the BBC: “She has made clear our commitment ot supporting democracies in Afghanistan and Iraq ecause there is a very real threat to our country from this transnational terrorist group and it is in our national interest that we do our best to help those countries overcome the terrorism that they face

“What she has made it clear that in future where we are going to commit British troops there has to be a very real threat to our country, it has to be in the British national interest that we intervene in these countries or an ally that is asking for help - that we should not simply embark on foreign adventures for the sake of it.”

Asked if she were is not ruling out future foreign military intervention, she said: “She is absolutely not ruling it out – on the contrary we are increasing our effort both in Afghanistan and Iraq because there are terrorist groups there that threaten our own country.”