GEORGETOWN, Guyana, (AFP) — Guyana President Irfaan Ali said on Tuesday that he is open to “amicable discussion” on any topic with his Venezuelan counterpart this week in a high-tension summit — except for the territorial claim by Caracas on a contested oil-rich region.

That matter must be decided by the International Court of Justice (ICJ), Ali said on X, formerly Twitter.

“I have already made it clear that the #ICJ will determine the controversy surrounding the borders of Guyana and Venezuela. We are firm on this matter and it will not be open for discussion,” Ali said.

Ali released on X a copy of a letter he sent to the host of Thursday’s summit, Ralph Gonsalves, prime minister of St Vincent and the Grenadines.

In it, he took issue with recent statements by Venezuelan President Nicolas Maduro, who says that a referendum December 3 in which Venezuelan voters overwhelmingly approved of his country’s claim on the oil-rich Essequibo region offers him a mandate.

Maduro later ordered his nation’s state-owned companies to grant licenses to exploit oil and gas in the contested area.

“I, too, have a mandate from the National Assembly of Guyana which is unanimous in its resolve that the land boundary is not a matter for bilateral discussions and the settlement of the matter is properly in the International Court of Justice,” Ali said.

Venezuela does not recognize the jurisdiction of the ICJ in the territorial dispute.

Guyana has administered Essequibo, which makes up more than two-thirds of its territory, for more than a century.

The decades-old dispute with Venezuela intensified after ExxonMobil discovered oil in Essequibo in 2015, helping give Guyana — population 800,000 — the world’s biggest crude reserves per capita.

Maduro on Monday assailed Guyana for allowing joint training flights between its military and US forces earlier this month.

Maduro said he hopes the summit “can address the main threats to the peace and stability of our countries, among them the involvement of the US Southern Command.”

Ali refuted that any military operation from Guyana would target neighbouring Venezuela.

“Any allegation that a military operation aimed at Venezuela exists in any part of Guyanese territory is false, misleading and provocative,” Ali wrote.