Senior officials from Russia, Ukraine, Germany and France failed to reach a breakthrough in talks on Thursday over a conflict in eastern Ukraine.

The officials met in Berlin amid continuing tensions over Ukraine. Germany and France are mediating the talks between Russia and Ukraine.

Ukrainian forces and Russian-backed armed groups have been engaged in sporadic fighting in eastern Ukraine. Concerns are rising that Russia may use the situation as a pretext for invading Ukraine.

Russian representative Dmitry Kozak said the meeting ended with no major results. He said the four parties agreed to continue their discussions on the implementation of ceasefire agreements reached in 2014 and 2015.

On Thursday, Russian and Belarusian forces began joint drills in Belarus. The United States and some other countries fear that Russia could use the opportunity to mobilize troops and invade Ukraine.

Senior officials from the four countries previously met in Paris in late January.