Venezuela said Tuesday it is conducting military exercises in the eastern part of the country, a move neighboring Guyana denounced as an "extraordinary escalation" of an ongoing border dispute.

Defense Minister Vladimir Padrino Lopez said the troop buildup, which Guyana had noticed with concern, was an "operational deployment exercise."

He said Venezuelans could rest assured "because we are really preparing ourselves ... even with all the fronts we face today," alluding to simultaneous border tensions with Guyana and Colombia.

Guyana's President David Granger said his cabinet was meeting with military and police chiefs to craft a response to Venezuela's movement of naval vessels and ground forces in the area.

Venezuela has been pressing claims to Guyana's Essequibo region, which encompasses two-thirds of the former British colony, since Exxon Mobil discovered oil in disputed waters off its coast earlier this year.

"We feel that Venezuela is treading a dangerous course at this point in time rather than seeking a peaceful resolution of the matter," Granger told reporters.

"Venezuela seems to be pursuing a very offensive and aggressive course," he added.

"What we have noticed during the month of September is an extraordinary escalation of Venezuelan military activity in eastern Venezuela," said the retired brigadier.

Calling the military build-up "very provocative," he said he would be raising the issue in his speech to the United Nations General Assembly next week.

Granger had said previously he will tell UN Secretary General Ban Ki-moon that Guyana is no longer interested in continuing a 23-year old mediation process, which Venezuela wants to revive.

Granger instead wants the International Court of Justice in the Hague to settle the border dispute.

Guyana maintains that valid land borders were set in an 1899 arbitration court decision, a ruling Venezuela has never recognized.

The latest round of recriminations followed Exxon Mobil's announcement May 20 it had made a significant oil discovery in an offshore concession granted by Georgetown.

Venezuela countered by unilaterally extending its maritime boundaries to include waters off the Essequibo region.

The tensions lately have been overshadowed by a month-long crisis on Venezuela's western border, which saw thousands of Colombians flee the country amid a government crackdown on migrants and smuggling.

Venezuelan President Nicolas Maduro and his Colombian counterpart Juan Manuel Santos agreed Monday to restore diplomatic contacts and work out their differences.