US impeachment: Democrats accuse Trump of ‘cover-up’

The top Democrat in the US Senate is accusing President Donald Trump of “orchestrating a cover-up”.

Chuck Schumer has called for current and former White House aides to testify at Trump’s impeachment trial over withholding aid to Ukraine.

But the White House is discouraging Trump’s acting chief of staff, Mick Mulvaney and former National Security Advisor John Bolton from giving evidence.

Al Jazeera’s Kimberly Halkett reports from the White House in Washington, DC.