Iran's President Masoud Pezeshkian has declared that Tehran will not surrender in its confrontation with the United States, while affirming his belief in diplomacy as a path forward.

The statement came amid a turbulent day of international diplomacy on the sidelines of the United Nations General Assembly, where Pezeshkian is among the world leaders expected to address the body.

The day had opened with US President Donald Trump issuing stark threats against Iran, but concluded with a three-hour meeting between American and Iranian mediators. Trump described the talks as "very good."

Trump also held a high-level meeting with Ukrainian President Volodymyr Zelensky during the same period. Both sides said they wanted the war in Ukraine to end before winter.

Zelensky is also scheduled to address the UN General Assembly, as world leaders gather in New York seeking ways to resolve the two conflicts currently dominating international politics.