The three countries overseeing the 1994 peace agreement for Angola -- the United States, Russia and Portugal -- are drawing up a United Nations resolution threatening further sanctions against the former rebel movement, UNITA.

The resolution is likely to be voted on next week.

Correspondents say the new measures could include cutting off some of Angola's diamond trade which is controlled by UNITA.

UNITA is already subject to an arms embargo and a travel ban on its leaders.UNITA has failed to hand over four central areas still under its control by a deadline set for the end of last month; it now says it will do so by June the twenty-fifth.