WASHINGTON — The Trump administration has pledged to take a tougher stance toward China’s purchases of American know-how in its quest to compete more forcefully with the United States.

So few people expected that, during Mr. Trump’s visit to Beijing last week, a major Wall Street bank would announce it had teamed up with an arm of the Chinese government to make up to $5 billion in deals in the United States.

That deal — between Goldman Sachs and China’s sovereign wealth fund, the China Investment Corporation — illustrates the deep divisions in Washington over China’s trade and investment practices, as well as the complexities of policing the flow of Chinese money into the United States.

On Wednesday, a week after some Trump administration officials praised the deal as one of many that would help American businesses, a congressional commission recommended that lawmakers consider prohibiting entirely the acquisition of United States assets by Chinese state-owned entities — a move that could stop buyers like C.I.C. from reaching major American deals.