By Sabine Siebold
WARSAW (Reuters) - German Chancellor Angela Merkel and Turkish President Tayyip Erdogan tried to clear the air on Saturday in their first private talks since the German parliament infuriated Ankara by branding the 1915 massacre of Armenians by Ottoman forces a genocide.
Officials said the meeting on the sidelines of a NATO summit in Warsaw lasted longer than the scheduled 45 minutes. Both leaders were expected to make statements later in the day.
Relations between Turkey and Germany - vital partners in efforts to curb mass migration to Europe - have been strained since the Bundestag passed the Armenian resolution on June 2. Ankara withdrew its ambassador from Berlin and threatened unspecified retaliation.
A source close to the Turkish presidency said Erdogan expressed his disappointment at the resolution to Merkel, who said she would do her utmost to ensure this event would not harm German-Turkish relations.
The source said Merkel also expressed satisfaction with the way Turkey was keeping its word in preventing refugees and migrants crossing the Aegean Sea to Greece after more than one million flooded into Europe last year, most ending up in Germany.
German officials would not comment immediately on the substance of the talks.
In apparent retaliation, German parliamentarians have been denied access to the Incirlik airbase in southeastern Turkey where some 250 German troops are participating in NATO operations against Islamic State militants in Iraq, prompting protests from the Berlin government.
The Turkish source said Merkel had raised the issue and asked Erdogan to restore access to Incirlik for lawmakers, who approve all military spending and investment.
Erdogan had replied that the airbase was not a place for "public shows and marketing" but Turkey would consider the request in the light of German statements on relations, the source said.
The two leaders also discussed intelligence cooperation in the fight against foreign fighters recruited by Islamic State in Syria, some of whom have returned to carry out attacks in Europe.
(Additional reporting and writing by Paul Taylor; Editing by Gareth Jones)