Christopher Wenk, the executive director for international policy at the U.S. Chamber of Commerce, second from right, and other lobbyists met with senators on Tuesday in Washington to discuss keeping Nafta intact.

WASHINGTON — Automakers, retailers and other business leaders stormed Capitol Hill on Tuesday in an extraordinary show of force against a Republican president they fear will cripple or kill the North American Free Trade Agreement, an outcome business leaders said could devastate their profits and harm the United States’ ability to compete in a global market.

More than 130 representatives from an array of industries met with senators on Tuesday to ratchet up pressure on lawmakers — many of whose constituents work for companies dependent on Nafta — to keep the deal intact.

The future of Nafta has appeared increasingly at risk in recent weeks as the Trump administration presses for significant changes that businesses and Canadian and Mexican negotiators say are nonstarters. The United States’ position has pitted the Trump White House against the business community — an unusual position for a Republican president who cast himself as a friend of the business community.

But the Trump administration’s proposals to rewrite Nafta have triggered alarm bells among automakers, retailers, agricultural companies and other businesses, who say the provisions the United States is pushing are “poison pills” that would hurt American companies and jobs. They have mounted an increasingly frantic effort to persuade lawmakers to preserve Nafta and push back against the provisions the United States is advocating.

The daylong lobbying session was organized by the U.S. Chamber of Commerce, which promised to send an “army” of lobbyists to Capitol Hill to fight the provisions. The group organized a similar visit to the House of Representatives on Oct. 11.

Business groups are worried about a number of United States proposals, including a “sunset clause” that would terminate the trade pact after five years unless the three countries voted to continue it. Businesses argue that the change would reduce the certainty the agreement gives them over their future operating environment — a key consideration when investing long term.

“Any proposals that would risk a crisis every five years on Nafta wouldn’t provide the certainty our members need to bring these investments forward,” said Greg Skelton, who heads the global affairs division at the American Chemistry Council, a lobbying group. “We are going to have a huge increase in domestic production, and there is no way we can consume that domestically.”

Mr. Skelton said the group has “picked up the pace of our meetings on hill.”

Manufacturers are also concerned about the administration’s demand to increase the amount of a product that is manufactured domestically. The United States wants to require 85 percent of the value of an automobile to be manufactured in North America to benefit from Nafta’s zero tariffs, up from 62.5 percent currently. The proposals would also require half of the value of cars manufactured in Canada or Mexico to be sourced from the United States.

Robert E. Lighthizer, the United States trade representative, left, with…