Venezuela's President Nicolas Maduro speaks during a meeting with representatives of the opposition, the Roman Catholic Church and Union of South American Nations' (UNASUR) at Miraflores Palace in Caracas April 10, 2014. [Photo/Agencies]

CARACAS - Venezuelan President Nicolas Maduro hosted opposition leaders on Thursday at the start of mediated talks intended to stem two months of political unrest that has killed dozens in the OPEC nation.

The meeting, brokered by foreign ministers from the Unasur bloc of South American governments, took place at the Miraflores presidential palace in Caracas and was broadcast live on TV.

"The road here was long and complicated, but it was worth it ... we are going to listen patiently, and with respect and tolerance, to the compatriots of the opposition," Maduro said in lengthy opening comments.

He cautioned against unrealistic expectations.

"There are no negotiations here. No pacts. All we're looking for is a model of peaceful coexistence, of mutual tolerance."

Some hardline opposition groups, including the party of jailed protest leader Leopoldo Lopez, boycotted the talks while dozens of demonstrators remain in jail.

Pollsters say approval levels for both Maduro and the opposition have fallen during the crisis, while an already slowing economy has suffered a further drag from the impact of violent clashes on businesses and transport.

Authorities said on Thursday that a policeman was shot dead in western Barquisimeto city while dispersing a demonstration, bringing the official death toll to 40.

Since protests began in early February, about 650 people have been injured, officials say. More than 2,000 people have been detained, and 174 are still behind bars.