Representative Brian Mast, the Republican chair of the House Foreign Affairs Committee, said on Tuesday that he is prepared to subpoena Nvidia CEO Jensen Huang if the executive does not respond by Wednesday to a congressional request for a closed-door briefing. The request concerns Huang's reported relationship with an alleged Chinese government agent, first disclosed by the New York Times.

Asked by ABC News whether he would consider issuing a subpoena, Mast answered: "Absolutely." Huang has not yet responded to the Republican request, according to the network's reporting on Tuesday.

Who issued the briefing request?

Three committee chairs sent Huang a letter last week: Mast of the Foreign Affairs Committee, Rick Crawford of the House Intelligence Committee, and John Moolenaar of the House China Committee. The letter requested a "joint, closed-door briefing" focused on Nvidia's "security protocols against foreign adversary espionage" — the company's internal safeguards against state-directed spying.

The request followed Nvidia's announcement on Sunday that it had opened an internal investigation into its chief executive. The New York Times reported that Huang had an affair with an alleged Chinese government agent identified as Alice Huang, a top executive at Megaspeed, a Singapore-based data company. The two Huangs are not related, according to the report's framing of the relationship.

The Select Committee on China separately sent a letter requesting that Huang appear for a closed-door briefing on November 18 concerning his relationship with Alice Huang. Nvidia has not publicly responded to that request either.

What does Mast want to ask?

Mast told ABC News he has a "lengthy" list of questions for the Nvidia CEO, including what correspondence he had with the Chinese government. Asked whether he worried about the national security implications, Mast said he was "100%" concerned, given that Huang runs the world's largest computer chip manufacturer.

"They're American chips. So we thank God that Jensen is an American entrepreneur. It's an American tech company because they're the best chips anywhere in the globe," Mast said. "But that being said, we don't want China to access them, to use them, to produce them like that."

What has Nvidia said?

Nvidia's board said it has "no reason to believe that either national security or Nvidia secrets were compromised" by the affair. A company statement added that Huang "fully supports the review" and will cooperate with it. ABC News reached out to Nvidia for comment from Huang for its story.

How are Democrats and the White House responding?

House Minority Leader Hakeem Jeffries told ABC News there are "real concerns" that need to be addressed. "We're going to need a full briefing, specifically as it relates to the Nvidia issue, so we can all get to the bottom of what has happened and what the implications are in terms of America's national security," Jeffries said.

President Donald Trump said on Monday that the FBI is investigating the matter. Trump said he spoke with Huang by phone that day, during which the CEO said he "didn't know" he was involved with an alleged Chinese spy. "He said he had absolutely no idea that the person in question was a spy," the president told reporters at a press briefing. It remains unclear whether, or when, the Trump administration alerted Nvidia that its CEO was the target of an alleged Chinese espionage operation.

The Chinese government has denied the allegations, calling them "baseless and purely slanderous smears against China." Neither Alice Huang nor her employer, Megaspeed International, responded to ABC News' request for comment.

What happens to a subpoena in January?

Any subpoena would face an immediate procedural obstacle. House Republicans lose control of their committees in January, when the chamber turns over to the Democrats. A subpoena issued before then would likely expire, and the incoming Democratic majority would need to issue a new one.