WASHINGTON — Treasury Secretary Henry Paulson told international leaders on Sunday that isolationism and protectionism could worsen the spreading financial crisis. With a new trading week dawning, U.S. lawmakers urged quick action by the Bush administration on measures to make direct purchases of bank stock to help unlock lending.

Sen. Chuck Schumer, chairman of the Joint Economic Committee, said an administration proposal to inject federal money directly into certain banks, in effect partially nationalizing the banking system, "is gaining steam."

"I am hopeful that tomorrow, the Treasury will announce that they're doing it. And they have to do it quickly ... markets are waiting," Schumer, D-N.Y., said.

The administration has not indicated when it would announce its next steps.

Democrats also are lining up behind House Speaker Nancy Pelosi's plan to bring lawmakers back to Capitol Hill after the Nov. 4 election to work on a second economic relief plan. The idea is to "give the middle class and the average citizen the same kind of relief that we try to give the financial sector," said Democratic Rep. Barney Frank of Massachusetts, chairman of the House Financial Services Committee.

Top Democrats are suggesting a $150 billion measure that would extend jobless benefits, provide more money for food stamps and finance some construction projects, such as rebuilding bridges and roads. It would also include either a tax rebate or tax cut.

Rep. Roy Blunt of Missouri, the second-ranking House Republican, said he would help on a plan "that makes sense" but is not laden with huge public works projects or bailouts for states that overspent on social programs.

As the International Monetary Fund and World Bank held their annual meetings over the weekend, Paulson warned the bank's policy-setting committee of the dangers of "inward-looking policies."

"Although we in the United States are taking many extraordinary measures to ease the crisis, we are not pursuing policies that would limit the flow of goods, services or capital, as such measures would only intensify the risks of a prolonged crisis," Paulson said.

Meanwhile, the World Bank pledged to protect poor and vulnerable countries and nations with rapidly developing economies. Mexican Finance Minister Agustin Carstens, who heads the bank's policy-setting committee, said the bank and the IMF will draw on the full range of their resources to help these countries.

Bank President Robert Zoellick told reporters the financial crisis "has been a manmade catastrophe. The actions and responses to overcome it lie in our hands."