The Trump team called the Senate's formal impeachment summons to the two articles of impeachment "a dangerous attack on the right of the American people to freely choose their president".
Trump's legal team, led by White House counsel Pat Cipollone and Trump personal lawyer Jay Sekulow, is challenging the impeachment on procedural and constitutional grounds, claiming Trump has been mistreated by House Democrats and that he did nothing wrong.
"This is a brazen and unlawful attempt to overturn the results of the 2016 election and interfere with the 2020 election, now just months away," the filing states. The lawyers said Trump "categorically and unequivocally" denies the allegations and encouraged lawmakers to reject "poisonous partisanship" and "vindicate the will of the American people" by rejecting both articles.
Trump's answer to the summons was the first salvo in what will be several rounds of arguments before the trial formally begins.
At issue in the impeachment cases are allegations Trump requested his Ukraine counterpart to investigate political rival Joe Biden at the same time his administration withheld hundreds of millions of dollars in aid from the former Soviet republic.
In other developments
•New documents released by House Democrats suggest Devin Nunes, the top Republican on the House Intelligence Committee, was more deeply involved than was previously known in efforts by allies of President Trump to dig up dirt in Ukraine on former Vice President Joe Biden. The materials were provided to the House by Lev Parnas, a Florida businessman who worked with Trump's personal lawyer Rudy Giuliani to try to persuade the Ukrainian government to launch an investigation into Biden. Parnas and his business partner, Igor Fruman, were indicted last year on charges of conspiracy, making false statements and falsification of records. The men have pleaded not guilty.
•Four Republican senators indicated they may join Democrats to call new witnesses to give evidence against President Trump. John Bolton, Trump's former national security adviser, and Mick Mulvaney, the acting White House chief of staff, top the list of potential witnesses Democrats want to hear from over Trump's withholding of US$400 million (NZ$605m) in military aid to Ukraine while seeking an investigation into political rival Joe Biden. Witnesses will only be called if at least 51 of the 100 senators vote for a motion to hear from them. There are 47 Democrats and independents, meaning the support of four Republicans would be needed.
- AP & Telegraph Group Ltd