Venezuelan President Hugo Chavez entered Colombia's bitter hostage standoff Friday, seeking to broker a deal between the government and leftist guerrillas to free hostages including politician Ingrid Betancourt and three U.S. defense contractors.

"I ask God that I can contribute in this issue of this humanitarian swap, in the search for peace, a peace for all of us," said Chavez, after stepping of his plane in Bogota on Friday.

Colombia's largest guerrilla group, the Revolutionary Armed Forces of Colombia, or FARC, is holding 45 hostages, including soldiers, politicians and the three U.S. contractors abducted more than four years ago. In return for releasing the hostages, the FARC is demanding that hundreds of guerrillas be freed, including two commanders serving time in the United States.

Success by Chavez, better know for his fierce criticism of Washington, in mediating a humanitarian swap could expand his influence and improve his image in the region.

But it is a risky move. He is stepping squarely into Colombia's civil conflict and generating optimism among the families of those long held captive by rebels.

While the U.S. government and other critics are frequent targets of his incendiary rhetoric, Chavez has seldom involved himself so directly with the internal affairs of another nation. He has long sought to maintain cordial relations with Uribe, despite his close ties to Washington.

Colombia's government and guerrillas agree in principle to the exchange but the details of a deal appear far from reach.

The FARC insists the government temporarily demilitarize a zone in southwest Colombia for the hand over of the hostages. Uribe has ruled this out. The rebels also demand that the released guerrillas be allowed to return to the insurgency, something the government has also rejected.

Nevertheless, the families of the kidnapped have expressed optimism the left-leaning Chavez can bridge the mutual distrust between the conservative government and leftist rebels.

Chavez was set to spend Friday mostly in meetings with Uribe at the president's farm just outside of the capital, Bogota.

The French-Colombian Betancourt was abducted as she campaigned for president of Colombia in 2002. She recently marked her 2000th day in captivity.

On Thursday, France's Nicolas Sarkozy phoned Uribe to express his support for the latest talks.

U.S. defense contractors Marc Gonsalves, Thomas Howes and Keith Stansell were snatched by the rebels after their plane crashed in southern Colombia in February 2003 as they were flying a surveillance mission. They are the longest held U.S. citizens currently held in captivity.