The United States on Monday lashed out at a United Nations conference promoting a two-state solution to the Israel-Palestine conflict that was hosted by its close allies France and Saudi Arabia.

The US State Department labelled the three-day event "unproductive and ill-timed", as well as a "publicity stunt" that would make finding peace harder.

The diplomatic push is a "reward for terrorism", the statement said.

The US deployed even harsher words against French President Emmanuel Macron, calling his decision to recognise a Palestinian state last week “counterproductive”, saying its Nato ally’s decision “undercuts our diplomatic efforts”.

France is hoping that the UK will follow its lead.