By Philip Pullella

VATICAN CITY (Reuters) - Venezuelan President Nicolas Maduro made a surprise visit on Monday to Pope Francis, who urged the embattled leader to alleviate people's suffering and negotiate with the opposition to solve his country's crisis.

The private, evening meeting took place in the framework of the "worrying" situation in Venezuela which was "weighing heavily on the entire population", a Vatican statement said.

It said the pope had urged Maduro to "courageously take up the path of sincere and constructive dialogue to alleviate the suffering of the people, most of all the poor, and to promote a climate of renewed social cohesion, which will allow people to look to the future of the nation with hope".

Despite its oil wealth, Venezuela has plunged into economic crisis, with many people skipping meals due to shortages and soaring prices.

Maduro was on a tour of oil-producing countries and first word of his presence in Italy came in the Vatican statement.

Significantly, the meeting with the pope came as a joint announcement in Caracas said the government and the opposition would hold talks on Sunday. It was not clear if Maduro would attend.

Venezuela has seen a worsening political standoff and protests since the suspension of a referendum drive to remove the unpopular Maduro.

Foes say Maduro, 53, has veered openly into dictatorship by sidelining the opposition-led congress, jailing opponents and then leaning on compliant judicial and electoral authorities to stop a recall referendum.

An official of Maduro's Socialist Party said the Vatican and Union of South American Nations (UNASUR), which has been leading a dialogue initiative, would monitor Sunday's talks on Margarita Island.

(Additional reporting by Diego Ore and Anggy Polanco in Venezuela; Editing by Richard Balmforth)