In an interview with German newspaper Frankfurter Allgemeine Sonntagszeitung on Sunday, Merkel discussed the refugee issue.

"The recent deal between the EU and Turkey aims at sharing the migrant load fairly as well as protecting the external borders of the block," Merkel said.

To a question on whether Turkish President Recep Tayyip Erdogan had disappointed Germany with regards to the refugee issue, Merkel replied: "No, I have known him for years. [...] Turkey is key partner for Germany."

The chancellor also said that she would have a chance to discuss the issue with Erdogan at the World Humanitarian Summit, which will be held on Monday and Tuesday in Istanbul.

Syria has remained locked in a vicious civil war since early 2011, when the regime of Bashar al-Assad cracked down on pro-democracy protests with unexpected ferocity.

The crisis saw more than 850,000 refugees cross from Turkey to the EU last year, prompting a deal for Ankara to accept returned migrants in a one-for-one exchange for Syrian refugees to be resettled in the EU.

The agreement included EU pledges to donate 6 billion euros ($6.8 billion) to aid refugees in Turkey, speed up the country’s EU accession and introduce visa-free travel for Turkish nationals.

Around 2.7 million Syrians who have fled the civil war in their country are being sheltered in camps inside Turkey, with many others living in cities and elsewhere.

The conflict in Syria has now driven more than 4 million people – a sixth of the country’s population – to seek sanctuary in neighboring states, making it the largest refugee crisis in a quarter-century, according to the UN.

Anadolu Agency