MOSCOW/KIEV (Reuters) - German Foreign Minister Heiko Maas on Friday urged both Russia and Ukraine to de-escalate the conflict in eastern Ukraine and said France and Germany were ready to help by monitoring naval traffic near the Crimean coast.

Slideshow ( 3 images )

Speaking in Kiev after a meeting with his Ukrainian counterpart Pavlo Klimkin, Maas again called for Moscow to release of the crews of three Ukrainian navy vessels it seized in November off Crimea. He said Russia must allow ships to pass through the Kerch Strait that leads to the Sea of Azov.

“All sides must contribute to the de-escalation of the conflicts,” said Maas in Kiev after meeting with Lavrov earlier in the day in Moscow.

Klimkin welcomed the offer to monitor shipping traffic through the Kerch Strait. Lavrov told reporters President Vladimir Putin had agreed to a proposal by German Chancellor Angela Merkel for German experts to monitor the strait a month ago, but they had still not arrived.

It was not immediately clear if French participation had previously been offered.

Events in the Kerch Strait have exacerbated tensions between Ukraine and Russia over the Moscow’s annexation of Crimea in 2014 and violence between Ukrainian forces and Russian-backed separatists in eastern Ukraine.

Maas bemoaned lack of progress in implementing the so-called Minsk peace accord aimed at ending the violence in eastern Ukraine, and also took aim at Kiev for what he called insufficient progress on combating corruption.

Despite its concerns over Russian actions, Germany has continued to back the Nord Stream 2 gas pipeline project that has drawn criticism from Washington and some European states.

Maas said Lavrov had renewed Moscow’s pledge to continue shipments of natural gas through Ukraine despite work on the Nord Stream 2 pipeline under the Baltic Sea.

Russian gas giant Gazprom is building the project jointly with Western partners Uniper, Wintershall, Engie, OMV and Shell.