U.S. President George W. Bush and his Colombian counterpart, Alvaro Uribe, have repeated their call for the release of all hostages held by Colombia's leftist FARC,  Revolutionary Armed Forces of Colombia rebel group.

U.S. National Security Council spokesman Gordon Johndroe, who is traveling with Mr. Bush in Europe said Mr. Bush spoke Thursday with President Uribe, who is in the United States for an official visit. The two leaders discussed Colombia's initiative to release prisoners as an incentive for the FARC to release its hostages, including three Americans.

While in Washington, Mr. Uribe is also expected to push for a free trade agreement, as Congress considers cutting anti-drug aid to the South American nation.

Democratic lawmakers have criticized Colombia's human rights record and expressed concern over the death-squad killings of labor organizers in that country. They say they may not approve the free trade agreement as a result.

Some also have expressed concern about a recent study showing that the cultivation of coca, the plant used to make cocaine, has increased in recent years.

U.S. lawmakers are considering cutting anti-drug aid to Colombia by 10 percent in 2008, and moving some of the funding from spraying coca crops to arresting drug traffickers.

Friday, Mr. Uribe is to appear in New York to honor former U.S. President Bill Clinton, who was in office when the United States began its joint effort with Colombia, called "Plan Colombia" to fight the international drug trade there.

Mr. Uribe's last trip to the United States to lobby for a free trade accord was in May.