When will US hit its debt ceiling and what happens if country defaults?

A debt ceiling fight is looming in the U.S. yet again, giving investors another worry for markets this year.

The U.S. government's deadline to raise the $31.4 trillion debt ceiling could be sooner than expected, analysts have said, pulling forward the risk of a debt default that could have wide repercussions across global financial markets.

Recurring legislative standoffs over the debt limits this last decade have largely been resolved before they could ripple out into markets. That has not always been the case, however: A protracted standoff in 2011 prompted Standard & Poor's to downgrade the U.S. credit rating for the first time, sending financial markets reeling.

Some investors worry the Republican party's narrow majority in Congress could make it harder to reach a compromise this time.