The decision by US President Donald Trump to pull his country out of the World Health Organization has prompted international concern.

Trump made the move via executive order on Monday shortly after being sworn into office. It was one of more than 40 such orders he signed, some of which reversed the policies of former president Joe Biden.

The WHO said in a statement on Tuesday that it "regrets" the decision and that the WHO and the United States "have saved countless lives and protected Americans and all people from health threats." It also said it hopes the US will reconsider, adding that it looks forward "to engaging in constructive dialogue to maintain their partnership."

Leaders in Europe expressed concern as well on Tuesday. European Commission Spokesperson Eva Hrncirova said, "We see with concerns the announcement to withdraw from the WHO organization by the United States, and we trust that the US administration will consider all this ahead of the formal withdrawal."

The United Nations is urging Trump not to carry through with another promise. It wants him to keep the US in a landmark climate framework known as the Paris Agreement.

Simon Stiell, the executive secretary of the UN Framework Convention on Climate Change, said, "The door remains open to the Paris Agreement, and we welcome constructive engagement from any and all countries."