WASHINGTON (Reuters/AFP) - United States President Barack Obama said on Monday it appears there has been progress in Senate fiscal impasse negotiations, but that there is a good chance the United States will default on its debts if Republicans are unwilling to set aside some partisan concerns.

Mr Obama emerged from the White House to visit Martha's Table, a charity organisation for low-income families where some furloughed government workers have been volunteering.

Mr Obama, who is to meet congressional leaders at the White House at 3pm Eastern Daylight Time on Monday (3am Singapore time on Tuesday), said he would be able to determine at that meeting whether the progress is real towards ending a government shutdown and avoiding a debt default ahead of a Thursday deadline. "My hope is that a spirit of cooperation will move us forward in the next few hours," Mr Obama said.

He said the impasse that threatens to throw the United States into a debt default could end "today" if Republicans cooperate. He also warned that a partial government shutdown, now on the cusp of its third week, had been "completely unnecessary", and hit out at the use of political brinkmanship designed to extract "extreme" concessions.

He warned "we stand a good chance of defaulting" unless real progress is made this week in the Senate and House of Representatives and if Republicans are not willing to set aside some aside some of their partisan concerns.

A debt default would send interest rates shooting up and the damage to the economy would be greatly magnified "if we don'tmake sure that the government's paying its bills and that has to be decided this week," he said.