Officials from the US and Iran clashed at the opening of the Nuclear Non-Proliferation Treaty review meeting, with tensions expected to continue throughout the four-week conference.
The dispute centred on Iran’s appointment as one of the conference’s vice-presidents as part of the Non-Aligned Movement.
The US, backed by Australia and the United Arab Emirates, opposed the move, while the United Kingdom, France and Germany raised concerns.
Russia objected to efforts to single out Iran.