The Senate inched closer to a deal to avoid default and raise the US borrowing limit, as politicians became more willing to compromise as the Tuesday deadline approached.

But all parties remained cautious on Sunday, as any deal would still have to be passed by the House of Representatives before President Barack Obama can sign it into law. Even as Senate leaders from both parties voiced optimism, the White House insisted that no agreement had yet been struck.

Any deal to raise the US debt ceiling would reassure investors as it would enable the government to pay interest on its debts and meet other bills as they came due, helping to preserve the US’s AAA credit rating. It would face its first big test with investors when Asian markets open on Monday morning.