A British warship has arrived in Guyana amid rising tensions between the former British colony and Venezuela.

The HMS Trent’s arrival on Friday led Venezuela to begin military exercises a day earlier, near its border with Guyana.

Brazil’s Ministry of Foreign Affairs urged the two South American countries to return to dialogue. It said other nations should avoid “military activities” that support either side.

The dispute is over Essequibo, a sparsely populated region that is the size of Florida and rich in oil and minerals. Venezuela has long claimed the sparsely-populated Essequibo region which is rich in oil and minerals, saying it was cheated out of the territory when Europeans and the US set the border.

Brazil’s statement on Friday called on Guyana and Venezuela to stay true to the Argyle Declaration, an agreement signed earlier this month in which their leaders said they would solve the border dispute through non-violent means.

The Ministry of Defence said the ship is visiting Guyana as part of a series of engagements in the region and that the vessel will conduct training exercises with Guyana’s military.

On its account on X, formerly Twitter, the ship posted photos of sailors welcoming Britain’s ambassador to Guyana and the chief of staff of Guyana’s Defense Force, Brig Gen Omar Khan.

The ship is generally used to intercept pirates and drug smugglers and recently conducted joint exercises with the navies of several West African nations.

In a statement on Thursday, Guyanese President Irfaan Ali said Venezuela “had nothing to fear” from the ship’s activities in Guyanese waters.

“Guyana has long been engaged in partnerships with regional and international states aimed at enhancing internal security,” he said. “These partnerships pose a threat to no one and are in no way intended to be aggressive.”

But on Thursday Venezuela began military exercises involving 5,000 troops in the eastern Caribbean, citing the visit by the British patrol ship.

In a nationally televised speech, Venezuelan President Nicolas Maduro accused Guyana of betraying the spirit of the Argyle Declaration.

“We will not let anyone push us around,” Mr Maduro said, surrounded by military commanders. He described Britain’s decision to send a warship as a threat from a “decaying former empire.”

Guyana has controlled Essequibo for decades, but Venezuela revived its historical claim to the region through a referendum in which voters were asked whether the territory should be turned into a Venezuelan state.

Venezuela says it was the victim of a land theft conspiracy in 1899 when arbitrators from Britain, Russia and the US decided the boundary.

Officials also argue that an agreement among Venezuela, Britain and the then colony of British Guiana signed in 1966 to resolve the dispute effectively nullified the original arbitration.

Guyana maintains the initial accord is legal and binding and asked the United Nations’ top court in 2018 to rule it as such, but a decision is years away.