The U.S. Supreme Court on Tuesday cleared the way for Donald Trump's administration to pursue mass government job cuts and the sweeping downsizing of numerous agencies, a decision that could lead to tens of thousands of layoffs while dramatically reshaping the federal bureaucracy.

The State Department announced plans to lay off some US-based diplomats and other employees, after the Supreme Court ruled that the Trump administration can go ahead with plans to slash the size of the federal workforce.

The Supreme Court's conservatives said it was a federal judge in San Francisco, not President Trump, who exceeded her authority.