Caracas: Venezuela on Wednesday said that UN Secretary-General Antonio Guterres "went too far" by referring a century-old border dispute with Guyana to the International Court of Justice.

Venezuela has been pressing a historic claim to Guyana's Essequibo region, which encompasses two thirds of the former British colony, since US oil giant Exxon Mobil discovered oil in off its coast in 2015.

Guterres sent the case to the ICJ on Tuesday following a failed UN-sponsored attempt that was aimed at brokering a settlement between Venezuela and Guyana by the end of 2017. "Guterres went too far" by attempting to bypass the Geneva Agreement, a 1966 border dispute deal that Venezuela reached with then-colonial power Britain, Foreign Minister Jorge Arreaza said.

Guyana's foreign ministry said Tuesday that it welcomed Guterres's decision, adding that the ICJ is the "appropriate forum for the peaceful and definitive settlement of the controversy."

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

The announcement in May 2015 of a significant discovery of high-quality oil in an offshore concession 190 kilometers (120 miles) off Guyana set off a round of recriminations between Venezuela and its eastern neighbor.

Guyana is pressing ahead with plans to drill for oil in the disputed waters, with production expected to begin in mid-2020.