President Donald Trump's "America First" stance is making the U.S. more isolated on the world stage, with the country quickly losing soft power to China, a former U.S. Treasury official told CNBC Thursday.

That shift is readily apparent at this week's annual meetings of the World Bank and the International Monetary Fund in Washington, according to Scott Morris, who oversaw U.S. global development policy and worked with the World Bank while in the Treasury Department during the Obama administration.

"You have a China that is looking to showcase its multi-trillion dollar 'Belt-Road' initiative with very high-profile events and then you have American officials who want to say no to everything: No to ambition at the World Bank, no to trade agreements," Morris told CNBC's "Squawk Box."

"That's a message that is a hard sell to the rest of the international community," he added.

The meetings of the IMF and the World Bank — two multilateral institutions that support global financial stability and offer development assistance, respectively — come as Trump indicated again Wednesday he might exit the North American Free Trade Agreement.

Morris, who is currently a senior fellow at the Center for Global Development, a think tank, said the administration's varying messages on international relationships were "troubling" and he expressed concern about how it could impact U.S. influence, particularly through the World Bank and IMF.

"The stark departure here is a message from this White House saying you should stop lending to a wide swathe of countries and really begin to wind things down," Morris said. "I think that's just not where the rest of the world is and, as a result, the U.S. is increasingly isolated."

His comments followed a Wednesday report by AidData that China could overtake the U.S. as the world's primary donor of foreign aid to most of the developing world. Trump has called for significant reductions in aid, prompting international concern and intense criticism from former White House officials and business executives.