Venezuelan President Nicolas Maduro hosted opposition leaders in Caracas for talks to put an end to months of political unrest.
A Vatican envoy read out a letter from the pope urging both sides to come to a peaceful agreement.
Many have been calling for Maduro to resign. He says he would only leave via the ballot box and rules out making any pacts.
Venezuelans have been demonstrating against high crime rates, inflation and a lack of basic foodstuffs, and polls show support for both Maduro and the opposition have fallen since the protests began.
As the meeting got underway, the news broke that a police officer had been killed, bringing the death toll of the unrest to 40.