US President Barack Obama has said he is willing to hold budget talks with Republicans, but not until they agree to lift "threats" against the economy.
Republicans "don't get to demand ransom in exchange for doing their jobs", Obama said, by demanding concessions in policy before reopening government.
The US government partially shut down operations on 1 October after Republicans who control the House of Representatives refused to approve a budget, saying they would only do so if Obama's healthcare reform law were delayed or stripped of funding.
Republican leaders on Tuesday renewed their calls for Obama to open negotiations over ending the impasses. Republican House Speaker John Boehner told reporters he was "disappointed that the president refuses to negotiate".
He said the president's position not to talk with Republicans "until [they] surrender" was not sustainable, and any discussions regarding the debt ceiling must address how the nation is "living beyond its means".
At the White House, Obama said he had spoken to Boehner and was "happy to talk with him and other Republicans about anything".
But Obama said any negotiations on the ongoing government shutdown or the debt limit "shouldn't require hanging the threats of a shutdown or economic chaos over the heads of the American people".
"We can't make extortion routine as part of our democracy," Obama said. "Democracy doesn't function this way. And this is not just for me. It's also for my successors in office, whatever party they're from."
He also warned of the repercussions of defaulting on the government's debt should Congress fail to raise the borrowing limit, currently set to be reached on 17 October.
Obama said breaching the borrowing limit could disrupt capital markets, undermine international confidence in America, permanently increase the nation's borrowing costs, add to its deficits and debt, and pose the "significant risk of a very deep recession".
Taliban mock US
Taliban militants fighting US troops in Afghanistan taunted Washington Wednesday over the government shutdown, accusing US politicians of "sucking the blood of their own people".
The Islamist militants issued a statement describing how US institutions were "paralysed", the Statue of Liberty was closed and a fall in tourist numbers had hit shops, restaurants and hotels in the capital.