German Foreign Minister Heiko Maas on Monday proposed that France and Germany mediate a major crisis between Moscow and Kiev after Russian vessels boarded and captured three Ukrainian ships.
Speaking on a visit to Madrid, Maas said that France and Germany would "strive together, and if needed as mediators, to avoid the conflict leading to a serious crisis" as country representatives met with their Russian and Ukrainian counterparts in Berlin.
Foreign ministry officials from all four countries were due to meet in Berlin on Monday in talks that had been planned before the crisis erupted on Sunday with Russia seizing the Ukrainian ships, accusing them of illegally entering Russian waters off the coast of Crimea in the Sea of Azov.
Maas said this would be "the first opportunity to gather together all parties in the conflict."
Ukraine's military was on high alert and its parliament was to vote Monday on a request from President Petro Poroshenko to impose martial law for 60 days.
The incident has raised fears of a wider military escalation and the UN Security Council was to hold an emergency session Monday. NATO also called an emergency meeting on the incident.
Maas said the long-running conflict pitting Ukraine against Moscow and Russian-backed rebels in the east of the country was "a danger for the security of Europe and we will both endeavour to finally find a political solution which we should have found a long time ago."