U.S. Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov plan to meet Saturday to discuss the escalating Ukraine conflict at this year’s Munich Security Conference in Germany. The U.S. has accused Russia of directly intervening on behalf of pro-Russian rebels in Ukraine, while Russia has criticized the U.S. for its support of an “illegal” government in Kiev.

The meeting comes at a critical time during the conflict in Ukraine. In recent days, pro-Russian forces pushed Ukrainian army and volunteer forces off about 200 square miles of territory and threatened to capture a key rail hub that would link rebel “capitals.” U.S. President Barack Obama said he is deciding on whether to arm the poorly equipped Ukrainian military, which Russian officials have repeatedly said would be seen as a provocation. It is important that progress is made and “discussions produce a result,” Lavrov said, according to Tass.

Lavrov will also meet with Ukrainian President Petro Poroshenko at the conference, which could have a more direct impact on the bloody conflict between the neighboring countries. Kerry joins Vice President Joe Biden in leading the American delegation to the conference. Follow the Munich Security Conference on Twitter for updates on meetings and speeches.

Over 400 top diplomats and experts were expected to descend on Munich this weekend to attend the largest gathering of its kind focused on international security and diplomacy. It doubles as a venue for diplomats to hold bilateral meetings on pressing issues. German Chancellor Angela Merkel will attend, fresh off her and French President François Hollande’s emergency talks with Poroshenko and Russian President Vladimir Putin.

Judy Dempsey at Carnegie Europe was critical of the state of European security ahead of the conference, questioning the role of NATO in securing Europe in the face of Russian aggression in Ukraine.

“For many different reasons, the Europeans and the Americans are reluctant to use force to stop Russia from dismembering Ukraine,” she said. “Even at the most fundamental level, such as providing basic security and protection to civilians, inaction by many European governments and the United States has been shameful.”