The presidents of Brazil, Mexico and Colombia called for Venezuela to release detailed voting tallies on Thursday, amid a dispute over presidential election results that has sparked protests.
Venezuela's electoral council proclaimed Maduro, who has been in power since 2013, the winner of the July 28 election with 51% of the vote.
But the country's opposition says its tally of about 90% of the votes shows its candidate Edmundo Gonzalez received more than double the support of the incumbent president, in line with independent polling conducted before the contest.
The opposition has released detailed tallies on a public website, but the government has so far not shared any information beyond a national total of votes for each candidate.
The current presidents of Brazil, Colombia and Mexico have traditionally been friendlier with Maduro and have adopted a more neutral stance on the election, as countries around the world call for release of full tallies and the US said Maduro should acknowledge a Gonzalez win.
"We call on the electoral authorities in Venezuela to move ahead quickly and let itemized ballot box level results be known publicly," Brazil, Mexico and Colombia said in a joint statement after a call between their presidents Luiz Inacio Lula da Silva, Andres Manuel Lopez Obrador and Gustavo Petro.
Results should be verified impartially, the countries said, all political actors should avoid an escalation of violence and electoral controversies should be solved via institutions.
"We reiterate our willingness to support dialogue efforts and the search for agreements that benefit the Venezuelan people," the statement said.
In response to election-related criticism, Venezuela has expelled diplomats from Argentina and five other countries - Chile, Costa Rica, Panama, the Dominican Republic and Uruguay.
Caracas and Lima each expelled each other's diplomats after Peru recognized Gonzalez as Venezuela's elected president.
Maduro has also requested a call with Lula, a Brazilian source said.
The disputed election has led to deadly protests that Maduro and his allies in the military have denounced as an attempted coup.
Human Rights Watch said on Wednesday it had received reports of 20 deaths in post-election demonstrations.
The protests had closed shops and caused cuts to public transport around Venezuela, which is mired in a deep and lengthy economic crisis marked by high inflation, but many places were returning to normality by Thursday.
Major government figures including Maduro have said Gonzalez and high-profile opposition leader Maria Corina Machado should be held responsible for the anti-government protests, with some going as far as to call for their arrests.
There have been more than 1,200 arrests of protesters, Maduro said on Thursday, and the government is seeking 1,000 more.