In a tweet on Tuesday, Trump says he has come to the conclusion that the inquiry is not really an impeachment, "it is a COUP, intended to take away the Power of the People."
In fact, a coup is usually defined as a sudden, violent and illegal seizure of government power. The impeachment process is laid out in the U.S. Constitution.
Trump claims in his latest tweets that the impeachment drive is aimed at blocking his agenda of protecting the Second Amendment, building a border wall and preserving religious freedom, among other things.
The State Department's inspector general is set to hold congressional briefings on Ukraine.
Staff from House and Senate committees are expected to hear Wednesday from the inspector general, who will brief them on documents Congress has requested from the State Department about Ukraine.
That's according to a Republican aide unauthorized to discuss the briefing and speaking on condition of anonymity.
The aide said staff from the foreign relations, appropriations, intelligence and oversight panels in both houses have been invited to the briefing.
The panels have requested documents and information about Ukraine, which has been central to the impeachment inquiry against President Donald Trump.
The Trump administration's former envoy to Ukraine, Kurt Volker, has confirmed he will speak to three House committees behind closed doors on Thursday.
That's according to a House official familiar with the meeting who spoke on condition of anonymity.
The official said the House Intelligence, Foreign Affairs and Oversight and Government Reform committees invited Volker to appear as part of their investigations into President Donald Trump's dealings with Ukraine.
Volker resigned last week after a whistleblower complaint detailed Trump's interactions with the Ukrainian president.
The official said former Ambassador to Ukraine Marie "Masha" Yovanovitch will appear Oct. 11. The committees agreed to the new date after she was originally scheduled to appear Wednesday.
Secretary of State Mike Pompeo told the panels in a letter Tuesday that the dates they had scheduled were "not feasible."
— Mary Clare Jalonick
Rudy Giuliani, the president's lawyer, has retained a lawyer.
Jon Sale, an assistant special prosecutor in Watergate, confirmed on Tuesday that he has been brought on by Giuliani, who received a congressional subpoena on Monday.
Giuliani is President Donald Trump's personal lawyer and was instrumental in his efforts to stymie special counsel Robert Mueller's Russia probe.
He also is at the center of Trump's efforts to push Ukraine to investigate the family of political rival Joe Biden.
Those efforts have prompted House Democrats to open an impeachment inquiry against Trump. They issued a subpoena Monday for documents related to Giuliani's dealings with Ukraine.
The chairmen of three House committees say they expect "full compliance" from Secretary of State Mike Pompeo as they investigate President Donald Trump's dealings with Ukraine.
House Intelligence Committee Chairman Adam Schiff, House Foreign Affairs Committee Chairman Eliot Engel and House Oversight and Reform Committee Chairman Elijah Cummings fired back Tuesday after Pompeo said in a letter that lawmakers are trying to "intimidate" and "bully" his employees. Pompeo said depositions scheduled by the panels are "not feasible."
The chairmen wrote Pompeo that "any effort to intimidate witnesses or prevent them from talking with Congress" is illegal and could constitute obstruction of justice in their ongoing impeachment inquiry.
The committees scheduled depositions this week with former Ambassador to Ukraine Marie "Masha" Yovanovitch and Kurt Volker, the Ukrainian envoy who resigned last week.
Ukraine's president says no one explained to him why U.S. military aid to his country was delayed.
President Volodymyr Zelenskiy told reporters Tuesday that he stressed the importance of the military aid repeatedly in discussions with President Donald Trump, but "it wasn't explained to me" why the money didn't come through until September.
The Office of Management and Budget staff said the $250 million in funding had been delayed because Trump was consulting with his national security team about it.
While delaying the aid, Trump asked the Ukrainian leader in a July phone call to "look into" his Democratic rival Joe Biden.
Zelenskiy insisted Tuesday that "it is impossible to put pressure on me." He also said he has never met or spoken with Trump's lawyer Rudy Giuliani, who has pushed for an investigation into Biden's son Hunter, who was on the board of a Ukrainian gas company.
Republican Sen. Chuck Grassley says a whistleblower who filed a complaint about President Donald Trump's dealings with Ukraine "ought to be heard out and protected" and his or her requests for confidentiality should be respected.
Trump said Monday that "we're trying to find out" the whistleblower's identity even though the person is protected by the Whistleblower Protection Act.
Some Republicans have criticized the whistleblower for relying in part on information from White House aides. Grassley says such second-hand information "should not be rejected out of hand."
Grassley says "no one should be making judgments or pronouncements without hearing from the whistleblower first and carefully following up on the facts."
The Iowa senator is a longtime advocate for whistleblowers and the chairman of the Senate Finance Committee.
Secretary of State Mike Pompeo says in a letter to the House Foreign Affairs Committee that Democrats are trying to "intimidate" and "bully" State Department employees and that depositions scheduled by the panel are "not feasible."
Three House committees have scheduled depositions with five current and former State Department officials over the next two weeks, including former ambassador to Ukraine Marie "Masha" Yovanovitch and Kurt Volker, the Ukrainian envoy who resigned last week.
The chairmen of the House Foreign Affairs, Intelligence and Oversight committees set an Oct. 4 deadline for Pompeo to produce documents related to their investigation of President Donald Trump's interactions with Ukraine. The probes are part of an impeachment inquiry.
House Democrats are moving aggressively against Trump lawyer Rudy Giuliani as part of their impeachment inquiry.
Giuliani has been at the heart of President Donald Trump's efforts to get Ukraine to investigate political rival Joe Biden's family.
On Monday they issued a subpoena to the former New York mayor for text messages, phone records and other communications that they referred to as possible evidence. They also are seeking documents and depositions from three of Giuliani's business associates.
The circle of officials with knowledge of Trump's phone call to Ukraine's president widened with the revelation that a Cabinet official, Secretary of State Mike Pompeo, listened in on the July 25 conversation. That call and the circumstances surrounding it are fueling the new Democratic drive for impeachment.