Watch: Biden attacks Trump in first speech since leaving White House

Former US President Joe Biden has used his first speech since leaving the White House to attack the work of his successor, Donald Trump.

Without referring to Trump by name, Biden said the new administration had "done so much damage and so much destruction" in its opening weeks.

The Trump administration had "taken a hatchet" to the social security system, Biden added, after it pledged to cut back staff at the agency that administers benefits.

Trump has said he is not cutting payments to retirees but instead targeting waste and fraud within the US public pension system.