The lone U.S. government representative at the United Nations climate gathering says the State Department made it harder for members of Congress to attend.
Some of Thursday's speeches reflected anger and dismay at U.S. policies but could not hide the ambivalence that many countries feel about this year's climate talks.
Ten years after nations adopted the Paris Agreement, its objectives are in jeopardy amid rising climate pollution and a political backlash against clean energy.
Clean energy is the "trend of our time," Chinese President Xi Jinping said while announcing modest targets for trimming the economic superpower's carbon pollution.