Theresa May has expressed regret over Donald Trump's decision to pull out of the Paris climate accord in a personal phone call with the US President.

Ms May did not put her name to a joint statement released by the leaders of France, Germany and Italy on Thursday evening but told Mr Trump of her belief the Paris agreement represented "the right global framework for protecting the prosperity and security of future generations".

A Downing Street spokesman said: "President Trump called the Prime Minister this evening to discuss his decision to pull the US out of the Paris Agreement.

"The Prime Minister expressed her disappointment with the decision and stressed that the UK remained committed to the Paris Agreement, as she set out recently at the G7.

"She said that the Paris Agreement provides the right global framework for protecting the prosperity and security of future generations, while keeping energy affordable and secure for our citizens and businesses.

"The President made clear that the door remains open to future US involvement in the Agreement."

The spokesman added: "The Prime Minister and President agreed on the importance of continued cooperation on wider energy issues."

A statement released by Angela Merkel's spokesperson on Twitter said she was "disappointed w/ Pres Trump's decision. Now more than ever we will work for global climate policies that save our planet".

Trump announces exit from the Paris climate agreement

She issued a joint statement alongside French President Emmanuel Macron and Italian Prime Minister Paolo Gentiloni that said the agreement could not be re-negotiated, pouring cold water on Mr Trump's claim he would try to do so.

The trio said: "We deem the momentum generated in Paris in December 2015 irreversible and we firmly believe that the Paris Agreement cannot be renegotiated, since it is a vital instrument for our planet, societies and economies."

Business leaders including Tesla chief executive Elon Musk and General Electric boss Jeff Immelt also criticised Mr Trump's decision.