Democrats leading the impeachment process in the U.S. House of Representatives have not formally called Trump as a witness in the inquiry into whether he used foreign policy to try to get Ukraine to investigate domestic political opponent Joe Biden.
Denying any wrongdoing, the Republican president has railed on Twitter and elsewhere against the inquiry and attacked witnesses by name in recent days.
House Speaker Nancy Pelosi, a Democrat, said on Sunday in a CBS interview that Trump has every opportunity to present his case, including coming before the intelligence committee holding hearings.
"Even though I did nothing wrong, and don't like giving credibility to this No Due Process Hoax, I like the idea & will, in order to get Congress focused again, strongly consider it!" Trump said on Twitter.
The public phase of hearings shifts into higher gear this week when a parade of officials will face questioning by Democratic lawmakers seeking details that could link Trump to a pressure campaign against Ukraine.
Eight more witnesses are due to testify in the second week of the televised hearings. They include Gordon Sondland, the U.S. ambassador to the European Union, whose direct interactions with Trump are likely to be a main focus in the investigation of whether the president made security aid to Ukraine contingent on it agreeing to dig up dirt on former Vice President Joe Biden.
Several witnesses testified last week that they were alarmed over the pressure tactics used against Ukraine, as well as the role of Trump’s personal lawyer, Rudy Giuliani.
The hearings could pave the way for the House to approve articles of impeachment - formal charges - against Trump. That would lead to a trial in the Senate on whether to convict Trump and remove him from office. Republicans control the Senate and have shown little support for Trump's removal.At the heart of the inquiry is a July 25 phone call in which Trump asked Ukrainian President Volodymyr Zelenskiy to open a corruption investigation into Biden and his son, Hunter Biden, and into a discredited theory that Ukraine, not Russia, meddled in the 2016 U.S. election.