(UTV|OVAL OFFICE) – US Democrats have ruled out a “witness swap” with Republicans in President Donald Trump’s impeachment trial.
Lawmakers who are seeking to remove the president from office hope to hear testimony from his former National Security Adviser John Bolton.
But Democrats refused any deal to allow the son of former US Vice-President Joe Biden to be called as a witness.
The trial could end next week, but Mr Trump’s fellow Republicans control the Senate and are unlikely to oust him.
Attending the World Economic Forum in Davos, Switzerland, on Wednesday, Mr Trump jokingly warned he might confront Democrats by coming to “sit right in the front row and stare at their corrupt faces”.
Mr Trump is accused of abuse of power and obstruction of Congress.
He denies using US military aid as a bargaining chip in an attempt to prod Ukraine into announcing an investigation to discredit his would-be Democratic White House challenger, Mr Biden.
Mr Trump has been touting corruption claims against Mr Biden, whose son Hunter held a lucrative board position with a Ukrainian gas firm while his father was US vice-president and in charge of American-Ukrainian relations.