Democrats and Republicans in the US Congress reached an agreement in principle on Wednesday to extend the federal budget by a few days and defer the threat of a government shutdown.

The agreement by Republican and Democratic leaders in the House and Senate would push back the start of a shutdown from Friday until March 8, giving policymakers some breathing room to try to reach a deal to fund the government.

"We are in agreement that Congress must work in a bipartisan manner to fund our government," they said in a statement.

They added that "a short-term continuing resolution to fund agencies through March 8 and the 22 will be necessary, and voted on by the House and Senate this week."

For several months, the United States has been deadlocked over the adoption of a finance bill for 2024.

The two parties have been entangled in partisan wrangling, and have only been able to pass a series of mini-bills to extend the US federal budget by a few days or months at a time.

The consequences of a government shutdown would be significant, and would include air traffic controllers going unpaid, some government agencies grinding to a halt, and the closure of America's much-beloved National Parks.

It must now be passed by the House of Representatives, the Senate, and then signed into law by President Joe Biden to postpone this threat.