In one of the more bizarre turns of events Friday, even for Trump, on Fox News Trump refused to commit to signing legislation overwhelmingly passed by Congress to support pro-democracy activists in Hong Kong.

He also claimed that China’s government would have “obliterated” Hong Kong and killed “thousands” of people there were it not for him.”

“If it weren’t for me, Hong Kong would have been obliterated in 14 minutes,” Trump said.

Trump’s apparent willingness to tie human rights issues to progress on the trade front drew rebukes from both Republicans and Democrats, who said such positioning risked compromising the United States’ role as a global defender of democracy.

“Make no mistake: President Trump’s words today do not reflect what the American people or the Congress think about President Xi’s oppressive policies toward the people of Hong Kong,” said Senator Chuck Schumer, the minority leader. “For a guy who promised to be tough on China, President Trump’s reliable deference to President Xi is all the more bewildering.”

Senator Rick Scott, Republican of Florida, said that a veto from Mr. Trump “would be a mistake. Congress spoke loud and clear that we #StandWithHongKong.” He added, “It’s more important than a trade deal.”