Ukraine's concerns that it might stop transporting natural gas to Europe due to the construction of the Nord Stream 2 gas pipeline are unreasonable, German President Frank-Walter Steinmeier said.

"I believe Ukraine's concerns that it might stop being a transit country in the future are unreasonable," Steinmeier said at a joint press conference with Ukrainian President Petro Poroshenko in Kyiv on Tuesday.

Germany is making efforts to ensure gas transportation via Ukraine and is holding negotiations to this end, he said.

"They [negotiations] are being held not only between Germany and Ukraine but also with the EU, and I hope these negotiations will bring about results in the near future," Steinmeier said.