The first trip to the UN's annual gathering of world leaders has particularly high stakes for David Granger, the recently elected president of Guyana. His country's neighbor, Venezuela, has renewed its claim that it is the rightful owner of two-thirds of the small South American nation's territory, and is massing troops along the border.

"For the first time, Venezuela has deployed rockets, armored vehicles, armed patrol boats in the river that forms the border with Guyana, and increased its troops," Granger told VICE News in an interview. "We have to render assurance that Guyana will be a safe and secure destination."

Venezuela has intermittently asserted sovereignty over Guyana's Essequibo region for more than a century, it's once again at the top of the agenda for Venezuelan politicians, including President Nicolas Maduro.

In 1899, a court of arbitration in Paris awarded the region to then British Guiana, much to the chagrin of Venezuela and the United States, which wanted to squeeze the United Kingdom out of the Western hemisphere. In 1962, four years before Guyana's independence, Venezuela pronounced the 1899 Paris decision null and void. The discovery of oil in the waters off Essequibo this year prompted Venezuela to renew its long dormant claims of jurisdiction.

Granger described the offshore oil find, which could bear fruit in five to seven years, as a "game-changer" that could fundamentally alter the economy of South America's third poorest country, which relies on production and extraction of rice, bauxite, gold, and other minerals — many of them in Essequibo — to eek out its annual budget. A thriving trade in heavily subsidized Venezuelan oil also supplies a large part of Guyana's economy.

"Our plan is to continue to invite foreign direct investment into our country, particularly to exploit our mineral resources, and also to make a sovereign wealth fund, to ensure the money is not squandered," said Granger. But those plans are up in the air as long as Venezuela keeps up its rhetorical and legal fight to take the oil-rich waters of Essequibo. Granger says he's concerned that investors may be scared away by Caracas' saber-rattling. "What we are seeing now is really a continuation of a pattern of provocation which has persisted for over half a century."

This week, after alleging Venezuela had deployed troops on the border, Guyana's military made a show of force in the capital, Georgetown, and elsewhere in the country. "It was not an attempt to engineer a military clash, it was simply a protective means of ensuring that Venezuela does not trespass on our territory," Granger said.

"We have to have the capability to determine if any incursion takes place," he added. "I cannot say when Venezuela is planning to have a military incursion."

On Friday, Venezuela's Ministry of Foreign Affairs said it had invited Granger for bilateral discussions in New York.

"We love and respect the people of the Cooperative Republic of Guyana," said Maduro, adding that "Venezuela has been the country that has most helped Guyana in its history, since it was the site of British Guiana."

Granger told VICE News that he had no plans to meet Venezuela's president one on one during his trip to New York, but was open to a scheduled meeting to be mediated by Secretary General Ban Ki Moon. A spokesperson for Ban's office told VICE News that the two leaders will be brought together with the Secretary General on Sunday evening.

Asked if he wanted Ban to tell Venezuela to leave his country alone, Granger said, "I'd use stronger language than that."

"The Secretary General knows his role, and we have asked him," he added. "He's already sent a delegation team to Guyana to assess the situation, and we expect that the team will report that the area is claimed by Venezuela is in effect occupied by Guyana and has been so for the last 300 years."

Venezuela insists that the dispute — which Guyana considers long resolved — should be tackled by a UN mediator. Granger says the International Court of Justice in the Netherlands should take up the matter.

Guyana has its own, smaller, claim to territory controlled by Venezuela. In 1966, the year of Guyana's independence, Venezuela captured Ankoko Island, along the border between the two countries. It has not returned the land.

"Venezuela is actually in illegal occupation of Guyana's territory," said Granger. "Whether they want to extend that illegality and expand the territory under occupation is another matter. Right now that is the worst case."

The dispute with Venezuela is in many ways a distraction for Granger, who on Friday gave a speech to the General Assembly endorsing the UN's new set of development goals for the next 15 years. His governing coalition, consisting of six parties, holds tenuous control after a narrow victory over the People's Progressive Party, which is supported largely by Indo-Guyanese citizens, descendants of indentured workers brought to the colony by British authorities. After running on a platform of inclusiveness, Granger, a historian and former general, says another goal is to beckon back Guyana's massive diaspora, which for decades left for the US, the United Kingdom, and elsewhere.

"I've always said that Guyana is a nation divided in two, half lives in North America, half lives in South America," he said.