U.S. President Donald Trump speaks during a joint press conference with Norwegian Prime Minister Erna Solberg (not seen) 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)