The long-running spat over the oil-rich Esequibo region, which is being heard by the International Court of Justice (ICJ), escalated over the weekend when voters in Venezuela rejected the ICJ's jurisdiction and backed creation of a new Venezuelan state.
Guyana has questioned the vote's legitimacy, put its armed forces on high alert and said Venezuela President Nicolas Maduro is disregarding ICJ orders about taking no action to change the status quo in Esequibo.
Comments by Maduro about authorising oil exploration in the area drew particular ire from Guyanese President Irfaan Ali, who sought to reassure investors like Exxon that have major projects offshore of Guyana.
The UK's Foreign Office said on social media that the recent steps by Venezuela were concerning, "unjustified and should cease".
The UK is concerned by the recent steps taken by Venezuela, with respect to the Essequibo region of Guyana. — Foreign, Commonwealth & Development Office (@FCDOGovUK) We believe this is unjustified and should cease. We are clear that the border was settled in 1899 through international arbitration.December 7, 2023
Brazilian President Luiz Inacio Lula da Silva said he was following developments with increasing concern and suggested multilateral bodies should contribute to a peaceful solution and that Brazil could host talks.
"We do not want and we do not need war in South America," Lula said.
Brazil's army intelligence has detected a build-up of Venezuelan armed forces near the Guyana border, according to a senior military source.
The US Southern Command, which provides security co-operation in Latin America, will conduct flight operations with the Guyanese military within Guyana on Thursday, the US embassy in Georgetown said in a statement.
"This exercise builds upon routine engagement and operations to enhance (the) security partnership between the United States and Guyana, and to strengthen regional cooperation," it said.
US Secretary of State Antony Blinken spoke with Ali late on Wednesday and reaffirmed the unwavering US support for Guyana's sovereignty, the State Department has said.
Analysts and sources in Caracas have said the referendum was a effort by Maduro to show strength and gauge his government's support ahead of the 2024 election, rather than representing a real likelihood of military action.
Maduro's government on Wednesday arrested opposition figure Roberto Abdul for alleged treason connected to the referendum and said there are also warrants out for three staff members at the campaign of opposition presidential nominee Maria Corina Machado.
A lawyer for Machado's party has said the staff always acted correctly.
A US State Department representative said it was aware of the arrest orders and "closely monitoring the situation".
