Michael Pillsbury, an informal China adviser to Mr. Trump, said the S.E.C. often makes the logical argument that Chinese companies would simply choose to list on exchanges in other countries.

“President Trump is demanding to know the origins of the virus and what Xi Jinping knew when about the cover-up,” Mr. Pillsbury said.

Other ideas are also being discussed, said Michael Pillsbury, a Trump adviser and director of the Hudson Institute’s Center on Chinese Strategy, including whether Chinese access to the big American platforms of YouTube, Twitter and Facebook could be limited. (The platforms are blocked in China, but are powerful vehicles for Chinese propaganda globally.)

The two countries already are working together behind the scenes. Michael Pillsbury, a senior fellow at the Hudson Institute who advises the Trump administration on China, pointed to efforts underway by the American biotechnology companies Inovio Pharmaceuticals, GeoVax and Gilead Sciences to develop a coronavirus treatment in China, some in partnership with Chinese companies.

Michael Pillsbury, a China expert at the Hudson Institute who advises the Trump administration, said he supported the emergency measures and that they might be escalated based on the situation.

Michael Pillsbury, a China scholar at the Hudson Institute who advises Mr. Trump, said that Mr. Trump’s campaign advisers have realized that the president’s supporters are less concerned about China’s record of human rights abuses or fears that it is an existential threat and more interested in having greater access to its market.