The U.S. intelligence community wants Silicon Valley to think twice about doing business with China.

Amid mounting national security concerns, Sen. Mark Warner, D-Va., said he and fellow lawmakers have held classified briefings with intelligence officials and American businesses, including major Silicon Valley and venture capital firms, to warn them about the dangers China presents.

The briefings, which began last fall, come as the U.S. is ramping up pressure on Chinese businesses amid concern over their ability to spy on American citizens and steal intellectual property.

“I’m a former venture capitalist," Warner told NBC News. "Until fairly recently, my views were similar to a lot of folks coming from the business world: I supported growing economic ties between China and the U.S., believing there were opportunities for both to benefit."

"But a few years and many, many classified briefings later, my views have changed, as China has," he said. "We have to increase awareness among U.S. companies, investors and universities about the tactics China is now using to undermine U.S. competitiveness, security and influence."

The push to uncouple U.S. and Chinese businesses points to a bipolar future divided by a technological "iron curtain," wherein the global geopolitical map is divided between countries that rely on U.S. technology and those that rely on Chinese technology.

The briefings have included a who's who of intelligence officials, including National Intelligence Director Dan Coats and National Counterintelligence Director Bill Evanina.

Republican Sens. Marco Rubio of Florida, Richard Burr of North Carolina, Susan Collins of Maine and John Cornyn of Texas have also been present at meetings.

The Financial Times, which was first to report on the meetings, noted that in "a highly unusual step," intelligence officials have shared classified materials with some of the executives.

The push is meant to impress the gravity of the situation upon business leaders who see the obvious economic benefits of doing business with China.

"While many in Washington understand the gravity of the threat, that’s not true across the country," Warner said. "For that reason, I have been convening meetings between the intelligence community and outside stakeholders in business and academia to ensure they have the full threat picture and hopefully make different decisions about Chinese partnerships."

The Trump administration's recent decision to bar Huawei from doing business with U.S. firms is seen by some as the point of no return for a cold war between U.S. and Chinese tech firms.

The administration has since granted a temporary reprieve on that ban in order to soften the blow.