Former U.S. president Jimmy Carter arrived in Syria Friday for a controversial meeting with Khaled Mashaal, the exiled political leader of the militant Palestinian group Hamas.
Carter, who has characterized his trip to the Middle East as a private peace mission, was also to meet Syrian President Bashar Assad.
Carter's trip has angered Israeli officials, who have shunned the former president, and drawn criticism from the White House. Dozens of congressmen, both Democratic and Republican, have written to Carter asking him not to meet with Hamas officials.
Both the U.S. and Israel have designated Hamas, which refuses to recognize Israel's right to exist, as a terrorist group.
During his trip, Carter sparked controversy after he hugged a senior Hamas politician, a move Israeli Foreign Ministry spokesman Yigal Palmor said "dignified" a group committed to Israel's destruction.
He also laid a wreath at the grave site of former Palestinian leader Yasser Arafat, whom the U.S. and Israel blamed for the breakdown of peace talks and subsequent wave of violence.
No agreement without Hamas: Carter
But the Nobel Peace laureate has rejected criticism about his trip, arguing that isolating Hamas does little to spur on the peace process between Palestinians and Israelis.
"You can't have an agreement that must involve certain parties, unless you talk to those parties to conclude the agreement," he said in a speech at the American University in Cairo. "You have to involve Hamas … They have to be involved in some way."
Carter said he told Hamas leaders from Gaza that they should stop rocket attacks on Israel, which have prompted deadly Israeli military assaults on the crowded Mediterranean coastal territory.
Any killing of civilians is "an act of terrorism," he said.
But Carter also said that for every Israeli killed in combat, between 30 to 40 Palestinians are killed because of the extreme military capability of Israel.
He also said that the Israeli blockade of Gaza, which has left the territory short of fuel and consumer goods, is an "atrocity." Israel has said the blockade is part of a crackdown spurred by increased Palestinian rocket attacks in southern Israel.