Migration and arms exports are among the tricky issues on the agenda.For many years now, Germany has been Turkey's most important trading partner and the largest foreign investor. More than three million people with Turkish roots live in Germany.

German Chancellor Olaf Scholz on Saturday defended his country's recently growing defence exports to Turkey, citing the membership of both countries in the NATO alliance as one reason. "Turkey is a member of NATO and that is why we always make decisions that there will be concrete deliveries.

Turkey's Recep Tayyip Erdogan thanked Germany's Olaf Scholz for his help in advancing a defence contract following talks in Istanbul on Saturday, although the pair remained starkly at odds over the Middle East crisis.

Germany has lifted curbs on military exports that were imposed after Turkey's 2016 ground offensive in northern Syria. During talks in Istanbul, the chancellor spoke of "concrete deliveries" to the fellow NATO member.