U.S. President Donald Trump (R, Rear) and Norwegian Prime Minister Erna Solberg (L, Rear) attend a joint press conference at the White House in Washington D.C., the United States, on Jan. 10, 2018. U.S. President Donald Trump said Wednesday that Washington could "conceivably" re-enter into the global Paris climate agreement, from which he announced the withdrawal last year. (Xinhua/Ting Shen)