UNITED NATIONS, Sept 25 (Reuters) - Palestinian President Mahmoud Abbas vowed on Saturday to do everything possible to make peace negotiations with Israel succeed and avoided any direct threats to break off the talks over settlements.

In a speech to the United Nations General Assembly in New York, Abbas said the Palestinians would expend every sincere effort to reach a peace agreement with Israel within a year.

He did not refer to Sunday's expiry of an Israeli freeze on new settlement construction in the West Bank. However, he made clear that Israel would have to cease all settlement activities if the direct negotiations with Israel are to succeed.

Israel must choose between peace and the continuation of settlements, he said.

Abbas has repeatedly threatened to break off the fragile negotiations with Israeli Prime Minister Benjamin Netanyahu over the settlements. The U.S.-supervised talks are aimed at reaching a peace agreement within a year.

Israeli Prime Minister Benjamin Netanyahu, whose rightist coalition government includes pro-settler parties, has so far deflected U.S. President Barack Obama's pleas to extend the freeze. But he has also said renewed construction in the settlements might be on a reduced scale.

(Reporting by Manuela Badawy and Louis Charbonneau; Editing by Sandra Maler)