Venezuelas opposition Tuesday withdrew from the latest round of crisis negotiations with authorities, insisting the government first release prisoners and allow a vote on the volatile countrys political future.

"We are staying in the dialogue system but we are not going to take part in today's meeting," said Jesus Torrealba, leader of the opposition MUD coalition.

His side insists the government release jailed opposition leaders and agree to hold a vote on whether Socialist President Nicolas Maduro should stay in office.

Maduro has refused both demands, despite insisting he is open to dialogue.

The center-right opposition blames Maduro's management for a deep economic crisis.

Maduro says the crisis is a US-backed capitalist conspiracy.

The dialogue aims to calm tensions as the center-right opposition demands a vote on removing Maduro.

The MUD claimed Maduro's side had agreed at the last round of talks to meet some of its demands.

"The government is not only failing to fulfill its promises, it is denying all the agreements," Torrealba said on the radio.

Maduro insists the issue of prisoners and a vote were never on the table.

A group of 14 jailed opposition leaders launched a hunger strike on Monday to demand the government release political prisoners and allow a vote to settle the crisis.

Analysts have warned there is a risk of unrest in Venezuela. Anti-government protests in 2014 led to clashes that left 43 people dead.

Maduro has the public backing of the military high command and of most state institutions.

Torrealba said his side would only meet with Vatican and regional Latin American mediators on Tuesday.