MUNICH - German Chancellor Angela Merkel on Saturday warned Syria not to meddle in Lebanon and Israel.

International pleas for "constructive" Syrian policies in the Middle East had so far not been heeded by Damascus, Merkel said in a speech opening the annual Munich Security Conference.

"Syria should have no doubt about the determination of the international community to protect Israel and support Lebanon," said Merkel.

The German leader also welcomed a recent agreement on forging a Palestinian unity government as a positive first step towards achieving a two-state solution allowing Israel to live side-by-side with an independent Palestine.

Merkel urged the new Palestinian government to meet three key international conditions for a resumption of direct aid: recognition of Israel, renunciation of violence and a pledge to abide by past treaties.

"We must not leave this region alone," said Merkel, adding that while Middle East peace efforts were making slow progress, it was vital to "keep trying."

Also taking part in the Munich meeting are Russian President Vladimir Putin, US Secretary of Defense Robert Gates, NATO chief Jaap de Hoop Scheffer and numerous foreign and defence ministers.