LONDON (AP) — The mood in financial markets was cautious on Monday as the partial shutdown of the U.S. government entered a seventh day and lawmakers appeared to be making little headway in raising the country's debt ceiling.

Stocks drifted lower and the price of oil dropped sharply as traders became nervous about the standoff in Washington, particularly over the debt ceiling. The U.S. has to raise its debt ceiling by Oct. 17. If it doesn't, the world's largest economy faces the possibility of defaulting on its debts, a move that would send shockwaves around the global economy and through financial markets.

Though most analysts think a deal to avoid default will be agreed on in time, investors are fidgety — uncertainty discourages investors from buying into risky assets, such as stocks. On Sunday, Republican House of Representatives Speaker John Boehner ruled out a vote on a straightforward bill to raise the government's borrowing authority without concessions from President Barack Obama before the deadline.