US President Donald Trump plans to lead a meeting of the heads of state of the UN Security Council on Iran in late September, his envoy Nikki Haley announced.

With the US now holding the presidency of the Security Council, Haley said the aim is to put further pressure on Tehran over its alleged violations of council resolutions. "President Trump is very adamant that we have to start making sure that Iran is falling in line with international order," Haley said.