The United States and China have clashed over Beijing's $1 trillion "belt and road" infrastructure program after the Security Council unanimously approved a bare bones resolution extending the mandate of the U.N. political mission in Afghanistan for six months.

Last year's resolution extending the mission's mandate for a year welcomed and urged further efforts to strengthen regional economic cooperation involving Afghanistan, including through the "belt and road" program linking China to Europe, Africa and other parts of Asia.

Council diplomats said China wanted that language included this year — but the U.S. objected.

U.S. deputy ambassador Jonathan Cohen said after Friday's vote that "China held the resolution hostage and insisted on making it about Chinese national political priorities rather than the people of Afghanistan," citing the "belt and road" initiative.