Iranian politicians burn US flag, chant 'death to America' after nuclear deal exit

Iranian MPs have set fire to a US flag and chanted "death to America" in parliament after Donald Trump withdrew from the country's nuclear deal.

A handout picture made available by the Iranian parliament office shows politicians burning a US flag during the parliament session. Source: AAP

A paper version of the American flag has been set on fire in Iran's parliament amid shouts of 'death to America' following President Donald Trump's decision to exit a 2015 nuclear deal.

Iran's parliamentary speaker Ali Larijani also hit out at President Trump, telling the parliament the US president lacks the mental capacity to deal with issues, the Iranian judiciary's website Mizan reports.

"Trump does not have the mental capacity to deal with issues," Mr Larijani said.

A symbolic copy of the Iran deal was also burnt during the parliamentary session.

It comes as European powers redoubled their efforts to keep the deal alive. 

France's foreign minister on Wednesday said the deal "is not dead", as China vowed to safeguard the accord.

The 2015 agreement curbed Iran's nuclear activities in exchange for lifting sanctions imposed by the US, United Nations and European Union.

The deal was agreed between Iran and the five permanent members of the UN Security Council - the US, UK, France, China and Russia - plus Germany. It was struck by Mr Trump's predecessor, Barack Obama.