On Thursday, the leftist rebels in Colombia released two hostages. The former hostages, politicians Clara Rojas and Consuelo Gonzalez, called for continued efforts to free hundreds of others held by the Revolutionary Armed Forces of Colombia (FARC).

In footage from Venezuelan television channel Telesur, the women were shown saying goodbye to their captors and talking to Chavez.

"Hello, president, Clara Rojas speaking. (...) We thank you from the bottom of our hearts for your help, thank you. (...) We are being reborn," Rojas, a former Colombian vice presidential candidate was shown telling Chavez in a telephone conversation.

"President, a thousand thanks for all your humanitarian efforts. Please, president, you cannot lower your guard. (...) Those who were left behind want you to know that. (...) We have to keep working," Gonzalez told Chavez.

The two women appeared to be in good condition and were visibly happy.

"At least she is fine, and the most beautiful thing is their mood and their smile," Rojas' mother Clara Gonzalez told Colombian radio after seeing footage of her daughter before meeting with her.

Red Cross spokesman Yves Heller said it was not known when Rojas, 44, and Gonzalez, 57, would return to Colombia. It was not known whether FARC planned to release other hostages in the coming days, he said.

Colombian Defence Minister Juan Manuel Santos expressed his satisfaction with the releases and said he hoped FARC would follow the move by freeing some 750 other hostages.

Chavez said the next objective was obtaining the liberation of all FARC hostages and "beyond that, to seek peace for Colombia."

The two women had been held by FARC for several years, along with hundreds of other civilians and Colombian officials, some of whom have been held for more than 10 years.

The Colombian government authorized the mission and ordered the suspension of military operations in a large area of the southern province of Guaviare.

In 2007, Chavez acted as a mediator in an effort to secure an exchange of some 50 politically relevant FARC hostages for hundreds of leftist rebels held in prison.

But he was dismissed from the job in November by Colombian President Alvaro Uribe, after talking directly with a Colombian general after he had specifically been asked not to do so.

In late December, Chavez orchestrated a high-profile international attempt to free Gonzalez, Rojas and her 3-year-old son, Emmanuel, who was born in captivity from a consenting relationship a rank-and-file rebel.

In Washington, US State Department deputy spokesman Tom Casey welcomed the release of the two hostages, praising Uribe but refused to highlight Chavez's role.

"They should have never been taken hostage in the first place. They've been held in captivity too long," Casey said.

"Anybody, including President Chavez, ... who has a role to play that is positive and that supports President Uribe and the Colombian government's efforts is to be welcomed," Casey added.

France, where Bentancourt holds dual citizenship, called for further efforts to secure the release of other FARC hostages.

The release of the two women had been an "important sign of hope for those still in captivity," Prime Minister Francois Fillon said in Paris.