The Taoiseach has rejected criticism from Fianna Fáil leader Micheál Martin that his comments on US Congress supporting Ireland over Britain on trade were provocative.

Speaking in Egypt at a summit of EU and Arab leaders, Leo Varadkar said Mr Martin was "always wagging the finger or sniping from the sidelines".

He added: "What I haven't seen from Fianna Fáil from their Ard Fheis or from anything in the past couple of months are any coherent policies or any real alternatives to what the Government is doing."

In his intervention to the plenary session of the summi, Mr Varadkar said he spoke about "the right to chose and women's rights, the right to love, the rights of the LGBT community, the sustainable development goals".

Asked if any Irish citizens who had gone to join the so-called Islamic State should be stripped of their citizenship, following recent controversy in the UK, Mr Varadkar said it should be considered on a case by case basis.

"I'd very loathe to revoke anyone's citizenship, provided they are a citizen by right, or acquired their citizenship lawfully or appropriately," said Mr Varadkar.

"I think it's bad practice to revoke someone's citizenship and render them stateless and leave them to be someone else's problem."