WASHINGTON — Citing danger to the national economy, the Bush administration came to the rescue of the U.S. auto industry this morning, offering $17.4 billion in emergency loans in exchange for concessions from the deeply troubled carmakers and their workers.

At the same time, Treasury Secretary Henry Paulson said Congress should authorize the use of the second $350 billion from the financial rescue fund that it approved in October to rescue financial institutions.

President Bush said, "Allowing the auto companies to collapse is not a responsible course of action." Bankruptcy, he said, would deal "an unacceptably painful blow to hardworking Americans" across the economy.

One official said $13.4 billion of the money would be available this month and next, $9.4 billion for General Motors Corp. and $4 billion for Chrysler. Both companies have said they soon might be unable to pay their bills without federal help.

Ford Motor Co. has said it does not need immediate help.

Bush said the rescue package demanded concessions similar to those outlined in a bailout plan that was approved by the House but rejected by the Senate a week ago. It would give the automakers three months to come up with restructuring plans to become viable companies.

If they fail to produce a plan by March 31, the automakers will be required to repay the loans, which they would find difficult.

Bush's plan is designed to keep the auto industry running in the short term, passing the longer-range problem on to the incoming administration of President-elect Barack Obama.