Poroshenko, Mattis discuss fight against Russian aggression in Ukraine

Poroshenko stated this after a meeting with Mattis in Kyiv on Thursday, an Ukrinform correspondent reports.

"During today's talks we undoubtedly considered the issue of counteracting Russian aggression against Ukraine," he said.

According to Poroshenko, this is a key subject and "our joint challenge."

Mattis arrived in Kyiv to participate in celebrations on the occasion of Ukraine's Independence Day.

op