There was movement Thursday on a possible deal to raise the debt ceiling so the United States does not run out of money to pay its bills.
House Republicans have offered a six-week increase in the debt limit. Details on the offer were not immediately available.
White House spokesman Jay Carney says President Barack Obama is encouraged that, in Carney's words, "cooler heads seem to be prevailing in the House."
But Carney said the president would likely agree to a short-term debt ceiling deal only if no other conditions are attached to it.
The president has said letting the United States default on its debts would be a catastrophe for the global economy.
Democratic Senate Majority Leader Harry Reid said he is still wafting to see what the Republicans are offering.
On the other major issue hovering over Washington, the U.S. government shutdown, Reid said again Thursday there will be no negotiations with Republicans until the government is reopened.
He said the government shutdown, about to enter its 11th day, is causing pain and suffering across the country.
News of a possible debt ceiling deal sent U.S. markets soaring. The three major stock indexes rose more than 2% Thursday.
Republican House Speaker John Boehner has insisted on linking negotiations on spending cuts to any bill raising the debt ceiling. He has also demanded talks on the president's health care program before letting the House vote on reopening the government.
Treasury Secretary Jack Lew told a Senate panel that it would be a "grave mistake" to fail to increase debt ceiling by the October 17 deadline. He said the Treasury would then only have about $30 billion on hand and some incoming revenue, but not enough to pay all its bills.
Lew said the government should not have to choose between paying paying government bond holders or paying pensions and health benefits owed to older Americans.
Jay Carney, White House Spokesman:
"The president is happy that cooler heads at least seem to be prevailing in the House, that there at least seems to be a recognition that default is not an option."
Jack Lew, U.S. Treasury Secretary:
"The United States should not be put in a position of making such perilous choices for our economy and our citizens. There is no way of knowing the irrevocable damage such an approach would have on our economy and financial markets."