The refugee crisis is a "global issue" and to solve it we need greater cooperation among all international powers, Prime Minister Binali Yıldırım said on Saturday.

When asked about U.S. President Donald Trump's recent visa ban against seven Muslim-majority countries during a news conference with British PM Theresa May in Ankara, Yıldırım said the refugee crisis cannot be resolved by building higher walls, reminding that there are currently over 55 million refugees in the world, a number higher than the population of 150 countries.

Yıldırım said Turkey's allies need to provide more support to and share the refugee burden with the country.

On cooperation, Yıldırım said the UK and Turkey will increase their cooperation in trade and security as he and May agreed that the two countries' security officials work together to ensure the safety of their airports.

He added that the officials from both countries will start to work on a roadmap to sign a free trade agreement after Britain leaves the EU.Drawing on the U.K.'s relationship with Turkey, the British PM said, "The relationship between Turkey and the United Kingdom has always been important, but it is arguably even more vital today. For Turkey sits on the frontline of some of the most difficult and serious challenges we face.

"This relationship is central to our capacity to tackle the terrorist threat to the U.K. Turkey already does a huge amount to disrupt the threat posed to our countries by terrorists including foreign fighters leaving Syria," she added.

Regarding Syria, where both countries are working together to fight Daesh and create the conditions for peace, the challenge of mass migration, she said, "The United Kingdom is committed to doing all it can to help."