And Representative Carolyn B. Maloney, the New York Democratic who is vice chairwoman of the Joint Economic Committee, said she was glad that President Bush “now recognizes the severity of current economic conditions” and was not linking the stimulus package to permanent tax cuts. “But is not yet clear that he would agree to targeting a plan toward people most in need,” she said.

At the White House, with members of his economic team flanking him, Mr. Bush said, “We’re in the midst of a challenging period.” But he said the American economy remains remarkably resilient and has overcome big challenges before.

The president said he based his overall optimism on the virtues of American workers, who “have shown time and again that they are the most industrious, creative and enterprising people in the world.” Mr. Bush again urged Congress to pass legislation to modernize the Federal Housing Administration and enable it to provide additional help for struggling homeowners.

Mr. Bush tried to dispel any sense that the White House was shocked into action by the drumbeat of bad economic news over the past few days. He said that, in fact, he and his economic team had begun a “thorough assessment” of conditions before he left for his trip to the Middle East.

But there was no mistaking the importance the White House attached to the president’s remarks. He was originally expected to deliver them at a plant in Frederick, Md., which he visited this afternoon, but his remarks were rescheduled for late morning at the White House. In his visit to the plant in Frederick, Mr. Bush said, “We need to get this deal done and get it out,” The Associated Press reported.

Treasury Secretary Paulson, in a briefing after the president’s White House remarks, said: “The cost of not acting has become too high. We must act now.”

Mr. Bush also offered a reminder that economic volatility is to be expected. “In a vibrant economy, markets rise and decline,” he said. “We cannot change that fundamental dynamic. As a matter of fact, eliminating risk altogether would also eliminate the innovation and productivity that drive the creation of jobs and wealth in America.”