The leaders of the world's 20 most powerful countries have agreed to step up border controls and aviation security in the wake of the Paris attacks that killed 129 people, according to a draft statement seen by Reuters on Sunday.

The heads of the Group of 20 (G20) largest economies, meeting in Turkey, condemned the attacks claimed by Islamic State as "heinous" and said they remained united in fighting terrorism, according to the draft document.

The finalised document is due to be released later on Sunday.

Meanwhile, the leaders will agree on Monday that migration is a global problem that must be addressed in a coordinated way, in a diplomatic coup for Europe and Turkey, a draft communique showed.

The leaders will also agree that all countries should help manage the migrant crisis, which is expected to bring a million people from the Middle East and Africa to Europe this year alone, through accepting refugees and humanitarian aid.

Europe and Turkey, the most heavily hit by the crisis, had been pushing for the G20 to recognise the issue as a global problem and help to deal with it financially, despite opposition from China, India and Russia.

"We call upon all states to contribute to responding to this crisis, and share in the burdens associated with it, including through refugee resettlement, other forms of humanitarian admission, humanitarian aid and efforts to ensure that refugees can access services, education and livelihood opportunities," the draft, seen by Reuters, said.

The draft has yet to be accepted by all and is to be published on Monday.

G20 leaders will also agree to step up financing for international organizations dealing with migrants, as requested by Europe, and to address the root causes of migrant displacement, such as the war in Syria, the draft said. - Reuters