German Chancellor Angela Merkel (R) shakes hands with visiting Russian President Vladimir Putin at the Schloss Meseberg, north of Berlin, Germany, on Aug. 18, 2018. German Chancellor Angela Merkel and Russian President Vladimir Putin held talks in north of Berlin on Saturday, with the topics ranging from Syria, Ukraine, Iran as well as the Nord Stream 2 gas pipeline project. (Xinhua/Shan Yuqi)

BERLIN, Aug. 18 (Xinhua) -- German Chancellor Angela Merkel and Russian President Vladimir Putin held talks in north of Berlin on Saturday, with the topics ranging from Syria, Ukraine, Iran as well as the Nord Stream 2 gas pipeline project.

The meeting came after Merkel's visit to Sochi in May. Before holding talks at the Schloss Meseberg outside Berlin, the two leaders addressed reporters.

"I am of the opinion that controversial issues can only be addressed in dialogue and through dialogue," Merkel said.

On the planned Nord Stream 2 pipeline to transport Russian gas to Germany, Merkel said Ukraine must continue to play a role in the transit of gas to Europe once Nord Stream 2 is in place. She welcomed the start of discussions among the EU, Ukraine, and Russia on the issue.

"I would like to stress that the main thing is that the Ukrainian transit -- which is traditional for us -- meets economic demands," Putin said, adding that Nord Stream 2 was exclusively an economic project.

The U.S. opposes the pipeline project as he believed that it will increase Germany's dependence on Russia for energy. Ukraine fears the pipeline will allow Russia to cut it off from the gas transit business.

Putin also urged Europe to intensify humanitarian aid to Syria so that refugees could return home. He warned Europe that millions of refugees from Jordan, Lebanon and Turkey would be potentially a huge burden for Europe.

For her part, Merkel said it was first of all to avert humanitarian crisis in Idlib, Syria and the surrounding region, and said she and Putin had already discussed the issue of constitutional reforms and possible elections when they last met in Sochi.

On Iran, the Russian president said he would discuss with Merkel the Iran nuclear deal between world powers and Iran.

Merkel warned on Friday against expecting too much from her discussions with Putin, saying it would be a work meeting from which no specific results are expected.