Venezuelan President Nicolas Maduro said Sunday that opposition leader Leopoldo Lopez, who is under house arrest, attended meetings between the opposition and the government, adding that a "dialogue" is under way between the two sides, although the anti-government forces say it is merely an "exploratory" process.

"Mr. Leopoldo Lopez, despite his status as a criminal, has been authorized by me, as head of the penitentiary administration, to attend meetings," said the president during a social movement event known as "We're All Venezuela" in Caracas.

In response to Maduro's remarks about Lopez attending meetings in the dialogue process, opposition lawmaker and negotiator Luis Florido on Sunday denied that assertion.

"It's untrue. Maduro is lying because he knows that the international community is pressuring for his exit through democratic elections and guarantees," said the opposition figure on Twitter.

Maduro referred to meetings between the government and the opposition - which the latter has called "exploratory meetings" - and reaffirmed that they constitute a "dialogue."

"Sixteen hours speaking about the future of Venezuela, the different issues. What is that called? Dialogue, conversation," Maduro said.

Maduro also emphasized that the meetings are the result of "months" of work and he thanked Dominican President Danilo Medina for his "personal effort" in getting the process going, given that the latter has been the main promoter and the host of those meetings.

"I can tell you that there have been dozens, if not hundreds, of meetings between the opposition" and the Venezuelan government, Maduro emphasized, adding that there were "private meetings" held all during 2016 and 2017.

Apart from Lopez, Maduro said that the opposition chief of the Venezuelan Parliament, Julio Borges, and former Zulia state governor and presidential candidate Manuel Rosales had attended some of the meetings.

Representatives of the Venezuelan government and the opposition met this week in Santo Domingo at the start of a prospective dialogue process, with the next meeting scheduled for Sept. 27.

The opposition representatives say that there will be no formal dialogue until the government agrees to a set of conditions they have put on the table, including the release of political prisoners.