Colombian Gustavo Petro arrived in Venezuela on Tuesday for the first presidential-level talks since the neighbors resumed diplomatic ties after a three-year hiatus.

Petro will sit down with his counterpart Nicolas Maduro in Caracas, in what will be the first visit by a Colombian president to Venezuela’s capital since 2013.

“After all this time, there’s a lot to talk about,” Petro said at the military airport in Bogota, before leaving for Caracas to end what he described as “years of political vacuum between two neighbors.”

According to the Colombian presidency, trade, migration and Venezuela’s “re-entry into the inter-American human rights system” were among the items on the agenda.

Venezuela severed diplomatic ties in 2019 after increasingly strained relations with Petro’s predecessor Juan Manuel Santos and conservative Ivan Duque – whom Maduro even accused of orchestrating plots to assassinate him.

The final drop came when Duque backed Venezuelan opposition leader Juan Guaido – who was recognized by dozens of countries as the winner of Maduro’s claimed 2018 election.

Embassies and consulates in both countries have been closed and flights between the neighbors have been suspended.

Since Petro Duque succeeded in August, Colombia’s first left-leaning president has sought to improve ties with Venezuela’s populist left-wing government.

Caracas and Bogota officially resumed diplomatic relations on August 29 by sending ambassadors to each other’s capitals.

Guaido on Tuesday criticized Petro’s decision to “visit dictator Maduro… and call him ‘president'”.

It was an “action that could dangerously normalize human rights abuses … and the worst migration crisis in the world,” he wrote on Twitter.

According to the UN, more than seven million Venezuelans have left their country since 2014.

Some 2.5 million are finding themselves in Colombia as part of an open-door policy implemented under Duque to support Guaido.

Aside from the migration, Petro said he and Maduro would talk about protecting the Amazon rainforest and “democratically building” the region.

In September, Colombia and Venezuela reopened their shared 2,200-kilometer (1,350-mile) border to vehicles carrying goods — as a first step toward resuming trade ties worth about $7.2 billion in 2008, but only $400 million US dollars last year.

Petro was elected on the basis of ambitious environmental, economic and social changes and making peace with armed groups who are fighting on despite the 2016 Colombian peace deal.

A string of recent victories for the left in South America now appear to have placed Maduro in a stronger position.

On Monday, he said he spoke with Brazilian President-elect Luiz Inacio Lula da Silva to “resume the binational agenda of cooperation,” which has been all but paralyzed under far-right leader Jair Bolsonaro.