CARACAS, Venezuela -- Key leaders of Venezuela's opposition have agreed to sit down with President Nicolas Maduro's government for talks aimed at defusing the nation's political crisis, now entering its third month.

The announcement followed a closed-door meeting Tuesday between Maduro and representatives of the opposition. The two sides agreed that talks aimed at reconciliation would be held in public and would begin shortly under the supervision of the foreign ministers from Brazil, Colombia and Ecuador, as well the Vatican's diplomatic envoy in Venezuela.

Opposition leaders for weeks had resisted Maduro's invitation for dialogue, but they changed course after receiving assurances from visiting South American diplomats that the socialist government is open to discussing a four-point agenda it has put forth as a starting point for talks. Their proposals include an amnesty for jailed government opponents, the creation of an independent truth commission to determine who is to blame for violence and the disarmament of groups loyal to Maduro.

While mistrust is still running high, just the opposition's willingness to sit down with the government represents a potential breakthrough that could help ease tensions after weeks of deadly protests that have rocked Venezuela but so far pose little threat to Maduro's rule.

Still many obstacles remain, foremost among them the lack of unity within the opposition.

Leaders of the broad Democratic Unity alliance that narrowly lost the presidential election to Maduro a year ago agreed to take part in talks. But one party, led by jailed hardliner Leopoldo Lopez, has already rejected the talks as a "political show" and said it won't stretch out a hand until the government frees all activists and ends a crackdown on protests.

Students, who have been the most combative in calling for Maduro to resign, also didn't partake in Tuesday's mediation efforts and are unlikely to abandon the streets anytime soon.

"We're firm believers that dialogue has to begin standing on two feet, never on one's knees," Lopez's Popular Will party said in a statement Tuesday night.

Vice-President Jorge Arreaza said the two-and-a-half hour preliminary meeting Tuesday between Maduro and members of Democratic Unity, including its executive secretary, Ramon Guillermo Aveledo, was cordial.

"We don't aspire to convince the opposition to become Chavistas nor for them to convince us to abandon the revolutionary path to socialism," Arreaza, flanked by South American diplomats, said in comments after the meeting.

The government says at least 39 people have been killed and hundreds more injured and arrested since students and mostly middle-class opponents of Maduro took to the streets in early February to condemn rampant crime, galloping inflation and record shortages of basic goods after 15 years of socialist rule.

Many also have called for Maduro to resign, leading his supporters to accuse the opposition of trying to foment a coup.

The U.S., which has sided with the opposition in criticizing Maduro's crackdown on the protests and jailing of critics, says it is supporting efforts to bring about dialogue.

Testifying Tuesday before the Senate Foreign Relations Committee, Secretary of State John Kerry pushed back against calls by Florida Republican Marco Rubio that the U.S. impose sanctions against the Maduro government for alleged human rights abuses, saying that with negotiations a possibility, now isn't the time for taking a tougher stance.

"This is a very delicate time," Kerry said. "I don't want to do something today that provides cannon fodder for them to use against me or us."