Lawmakers urged President Trump on Friday to pull back from a threat to impose tariffs on auto imports. Their warnings followed Trump declaring a national emergency to protect the domestic auto industry. The order gave U.S. trading partners six months to reach an agreement regarding imports of autos and auto parts. Trump has previously threatened to slap 25% tariffs on them.

"I am in the corner of autoworkers and made-in-America cars, but this is not a strategy to help U.S. workers. It will invite even more retaliation that will hurt our farmers, our ranchers, our manufacturers, while further isolating the United States," said Sen. Ron Wyden, D-Ore.

Rep. Jackie Walorski, R-Ind., urged the president to avoid another trade war. "I support the president’s goal of ensuring a level playing field for U.S. businesses and workers, but auto tariffs would be devastating to manufacturers in my district and across Indiana that make cars, RVs, auto parts, and more."

The White House said in a statement Friday that the president had "issued a proclamation directing the United States Trade Representative to negotiate agreements to address the national security threat, which is causing harm to the American automobile industry."

The proclamation was based on a Commerce Department report delivered to the White House in February. The report concluded "that imports of automobiles and certain automobile parts threaten to impair the national security of the United States," the White House said.

The administration was previously expected to deliver a decision on the report by Saturday, making Friday's announcement effectively a six-month delay in making a decision. The White House's top trade negotiators have been busy attempting to complete ongoing trade talks with China and with Canada and Mexico.

Senate Democratic Leader Chuck Schumer, D-N.Y., called the delay a "positive step" and warned that imposing auto tariffs would undermine the White House's other efforts retarding trade. "The pressure must be strong on China, not on our allies who we should encourage to join us in confronting China."

Other lawmakers warned the proclamation could build support for legislation that would rein in the president's ability to issue tariffs under Section 232 of the Trade Expansion Act, the section covering national security.

"I still have Qs abt the legitimacy of natl security as a basis for tariffs on allies Japan," Senate Finance Committee Chairman Chuck Grassley, R-Iowa, tweeted.

Sen. Rob Portman, R-Ohio, a former U.S. trade representative under the Bush administration, said the executive order stretched the definition of national security to the breaking point. "I’m glad the admin delayed imposing these tariffs, but minivans manufactured in Canada are not a national security threat to the US. We must rein in misuse of the Section 232 trade law while preserving this trade remedy tool for genuine threats to national security," he tweeted.

Trump has said that the decision on whether to initiate the tariffs would hinge on the outcome of trade negotiations with the European Union, one of the chief auto exporters to the U.S. "We are negotiating with them. If we do not make a deal, we'll do the tariffs," Trump told reporters in February, shortly after the Commerce Department delivered its report.

Those talks have yet to get seriously underway, having been stalled for months over the issue of whether the EU's agricultural subsidies and other protectionist policies will be up for negotiation. U.S. lawmakers have demanded they be included but EU officials have said that's a non-starter. The U.S. has also started preliminary trade talks with Japan, another major auto exporter.