Venezuela has long claimed Essequibo -- which makes up about two-thirds of Guyana's territory -- but has amped up its rhetoric since its neighbor began issuing licenses for oil companies to operate there.

Both countries pledged last year not to use force to settle the border dispute, which is currently before the International Court of Justice in The Hague.

"There are some inconsistencies between Venezuela's diplomatic and military posture," Guyana's Foreign Minister Hugh Todd told AFP.

The deployments "demonstrate Caracas' efforts to force Guyana to sidestep the case before the International Court of Justice and accept Venezuela's preferred approach of bilateral negotiations," Todd said.

His comments were prompted by a report earlier Friday by the Washington-based Center for Strategic and International Studies, which included satellite images showing the movement of troops and military assets closer to the two countries' border.

The report also indicated that Venezuela is expanding a military base in the border region.

In December, Venezuelan President Nicolas Maduro called a controversial non-binding referendum that overwhelmingly approved the creation of a Venezuelan province in Essequibo, sparking fears of a military conflict.

Tensions between the two countries, which had been easing, flared up again after US oil giant ExxonMobil announced on Tuesday it would drill two exploratory wells in the disputed waters.