VENEZUELAN President Nicolas Maduro said on Monday he was recalling the country’s ambassador to Guyana for consultations over a territorial dispute that has been reignited by oil giant Exxon Mobil.

The dispute, which stems from Britain’s annexation of the Essequibo region of eastern Venezuela to its then-colony of Guyana, was exacerbated in May when Exxon Mobil announced a significant oil discovery in disputed waters off the province, after Guyana unilaterally gave it permission to explore.

Venezuela called for a dialogue to settle the dispute according to the 1966 Geneva Agreement between the two nations.

But the new government of David Granger, elected by just 5,000 votes amid claims of fraud, accused Venezuela of being a “threat to regional peace and security,” echoing US President Barack Obama.

Exxon sued Venezuela for billions of dollars in compensation after new oil laws were introduced in 2007 requiring foreign firms to become minority partners with state oil company PDVSA.