A convoy, thought to be carrying Iranian diplomats, arrived at the Omani residence in Geneva on Thursday for indirect nuclear discussions with the United States.

An Associated Press journalist witnessed the convoy entering the residence. Earlier, another convoy was believed to have transported American negotiators to the location.

The nuclear negotiations between Iran and the United States in Geneva are being seen as a critical opportunity for diplomacy. The U.S. has positioned a significant military presence, including aircraft and warships, in the Middle East to exert pressure on Tehran for a deal.

President Donald Trump is keen on securing an agreement that would limit Iran’s nuclear ambitions, perceiving a strategic opening as the country grapples with internal issues, including rising dissent after last month’s widespread protests.

Meanwhile, Iran has insisted on continuing its uranium enrichment efforts, despite setbacks from a U.S.-ordered attack in June that targeted three of its nuclear facilities.

Iran meanwhile has maintained it wants to continue to enrich uranium even as its program sits in ruins following Trump ordering an attack in June on three of the Islamic Republic’s nuclear sites.