Map locating the disputed territory of Essequibo, between Venezuela and Guyana.
Map locating the disputed territory of Essequibo, between Venezuela and Guyana. AFP

US Department of Defense officials will visit Guyana next week, the South American country's vice president said Thursday, as he pledged that "all options" are on the table in its row with neighboring Venezuela.

Tensions are running high between Georgetown and Caracas, which has organized a December 3 poll to ask Venezuelans to consider annexing the Guyana-administered region of Essequibo, which makes up two-thirds of the tiny country.

Both nations claim the 160,000-square-kilometer (62,000-square-mile) region, in a dispute that has intensified since ExxonMobil discovered oil there in 2015.

Another major discovery in Essequibo in October added further to Guyana's reserves, making them greater than those of Kuwait or the United Arab Emirates.

"We're interested in maintaining peace in our country and in our borders, but we're going to be working with our allies to ensure that we plan for all eventualities," Guyanese Vice President Bharrat Jagdeo said Thursday -- including welcoming the establishment of foreign military bases.

"We were never interested in military bases, but we have to protect our national interest," he said, adding that defense cooperation was being pursued "with a number of countries."

Two teams from the US Department of Defense will visit Guyana next week, Jagdeo added.

"All the options available for us to defend our country will be pursued. Every option."

The dispute over Essequibo dates back to 1899, when an arbitration tribunal fixed the border between Venezuela and Guyana -- a former colony of both Britain and the Netherlands.

Venezuela maintains that the Essequibo River to the east of the region forms a natural frontier, recognized at the time of independence from Spain.

Venezuela's unilateral referendum will ask citizens if they should reject the 1899 tribunal decision, which Caracas says was "fraudulently imposed."

Also on the ballot is whether Venezuela should reject International Court of Justice jurisdiction over the dispute, and whether to grant Venezuelan citizenship to the people of an annexed Essequibo.

Guyana has the world's biggest reserves of crude per capita, while its neighbor sits on the largest proven reserves overall.