Jeremy Corbyn said the UK needs to end its “bomb first, talk later” foreign policy in the Middle East during a tour of a refugee camp in Jordan.
The Labour leader said the country needed to find a new approach and added that it should play a part in European schemes to resettle migrants post-Brexit.
Mr Corbyn, who was visiting a refugee camp in Jordan which has taken in millions of Syrians displaced by the violence, said the UK should do more to tackle Europe's migrant crisis.
"Whatever the outcome of Brexit, I think we should be part of a European-wide approach to this," he told Sky News.
"We have already done good work in saving life in the Mediterranean but what we haven't done is brought in the unaccompanied child minors that Lord Dubs - Alf Dubs - proposed in his amendment, which is now law."
Mr Corbyn said a Labour government would work to restart peace talks aimed at ending the bloodshed in Syria.
Labour would also support efforts to create and maintain local ceasefire zones, with the option of UN peacekeepers being deployed to underpin agreements.
Speaking after his visit to the Za'atari refugee camp, Mr Corbyn said: "We need to do everything necessary and effective to keep our people safe.
"That means ending the bomb first, talk later approach to international affairs, which has left a trail of destruction abroad and left us less safe at home.
"Politically we need to be doing a great deal more to try and bring about a ceasefire and an end to the war in Syria.
"The abuse of human rights, the destruction of lives, the destruction of society, is appalling by any stretch of the imagination. And refugees are now in all neighbouring countries and of course in Turkey, and in Greece and across Europe.
"Working to end long-standing conflicts, which create further violence and conflict, is at the heart of Labour's approach to domestic security."
