Brazil has called for “restraint” as tensions flared in a territorial dispute between Venezuela and Guyana, with Caracas launching a major military exercise near the contested, oil-rich Essequibo region.

“The Brazilian government is following the latest developments in the dispute surrounding the Essequibo region with concern,” said a statement from the foreign ministry on Friday.

“The Brazilian government believes military demonstrations of support to either party should be avoided so that the ongoing dialogue process can produce results.”

A British warship, the HMS Trent, also arrived in Guyana on Friday afternoon amid rising tensions, for open sea defence exercises in its former colony.

The UK’s defence ministry has said that 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 X account, the ship posted photos of sailors welcoming Britain’s ambassador to Guyana and the chief of staff of Guyana’s Defence Force, Brigadier General Omar Khan. They were also hosted at a formal lunch and provided with a tour of the ship’s capabilities.

Venezuela has for decades laid claim to Essequibo, claiming that the Essequibo river to the region’s east forms a natural border and has historically been recognised as such. President Nicolas Maduro’s government also held a controversial referendum on December 3 in which 95 percent of voters, according to officials, supported declaring Venezuela the rightful owner of Essequibo.

He has since started legal manoeuvres to create a Venezuelan province in Essequibo and ordered the state oil company to issue licences for extracting crude in the region.

The rising tensions have raised fears in the region of a potential conflict over the remote area of 160,000 square kilometres (62,000 square miles).

However, Guyana, of which Essequibo makes up more than two-thirds and hosts 125,000 of its 800,000 citizens, has administered the territory since the frontiers were determined by an arbitration panel in 1899.

Brazil’s President Luiz Inacio Lula da Silva has emerged as a peace broker of sorts, determined to prevent the current war of words over the disputed Essequibo region from escalating into something deadlier.

“If there’s one thing we don’t want, it’s a war in South America,” he said earlier this month.