BERLIN (REUTERS) - German Chancellor Angela Merkel voiced her concern about events in the Kerch Strait off Crimea during a meeting with Russian President Vladimir Putin at the G20 summit in Buenos Aires, her spokesman said on Saturday (Dec 1).

The two agreed to hold further talks about the issue at the adviser level among Ukraine, Russia, France and Germany, the spokesman said. Russia last week seized three Ukrainian naval ships and their crew when they tried to enter the Kerch Strait.

The spokesman said Merkel and Putin also discussed the situation in Syria, and agreed more effort should be made to work toward implementation of agreements by Germany, France, Turkey and Russia at a summit in Istanbul in October.