Syria's vice president said Saturday that conditions have improved for the release of Westerners held in Lebanon. Britain appealed for freedom of hostage Jack Mann on the second anniversary of his abduction.

The Syrian official, Abdul-Halim Khaddam, said circumstances for a possible release of the 13 Westerners missing in Lebanon were "more positive" than in the past."But we've learned that the hostage-holders have demands," Khaddam said. "They want Israel to free the Lebanese prisoners it holds. We hope that Israel would respond to international pressure."

Israel has said it is willing to release the estimated 300 prisoners it holds in southern Lebanon in exchange for the Western hostages and seven Israeli soldiers missing in Lebanon.

Israeli officials say they believe their soldiers are held by pro-Iranian Shiite Muslim groups and Palestinian factions. At least one soldier has been proclaimed dead by his captors.

After a meeting with Mann's wife, Sunny, British Ambassador David Tathem issued a statement urging those holding Mann and two other British hostages to free them.

"I appeal to those holding Jack Mann, John McCarthy and Terry Waite to set them free. They have been held long enough under appalling conditions," he said.

McCarthy, 34, a television reporter, was kidnapped April 17, 1986. Anglican Church envoy Terry Waite, 51, was kidnapped on Jan. 20, 1987, as he tried to negotiate the release of American hostages.