(Adds detail, quotes)
BERLIN, March 24 (Reuters) - Russia's stance on an OSCE mission in Ukraine was the only encouraging signal to come out of a phone call between Russian President Vladimir Putin and German Chancellor Angela Merkel on Sunday, a German government spokesman said.
Russia agreed on Friday with the 56 other members of the OSCE rights and security group to send a monitoring mission to Ukraine, but said the group had no mandate in Crimea, which Russia annexed after voters on the Black Sea peninsula chose to join Russia in a referendum dismissed by the West as a sham.
"There is an agreement between the chancellor and Putin that the OSCE mission is a welcome step ... and from our point of view, this is positive," German government spokesman Steffen Seibert said on Monday. "The discussion did not yield any progress on other issues."
Merkel sees the OSCE's decision to send a monitoring mission to Ukraine as a "first step to avoid further escalation" of the crisis, Seibert said.
Merkel pointed out "further worrying signs" to Putin such as reports that Russian troops are gathering at the border with Ukraine, said Seibert. She also told Putin that special attention needed to be paid to the situation in Moldova.
NATO's top military commander said on Sunday that Russia had built up a "very sizeable" force on its border with Ukraine and Moscow may have a region in another ex-Soviet republic, Moldova, in its sights after annexing Crimea.
Seibert also said Merkel had stressed Russia's responsibility for avoiding deaths in the Crimea region.
"The chancellor underlined in this phone call that Russia, due to its actions, is now de facto responsible for ensuring that it does not come to bloodshed in Crimea."
"The way the Ukrainian military has been handled in Crimea is therefore a reason for considerable concern," he added.
The two leaders agreed to remain in touch to try to increase the chances of reaching a political solution, Seibert said. (Reporting by Michelle Martin and Noah Barkin; Writing by Sarah Marsh; Editing by Stephen Brown)