Lawmakers in Democrat-controlled chamber set up first showdown Thursday over probe into Trump's efforts to push Ukraine to investigate opponents by withholding military aid

Tim Morrison to be first political appointee from White House to testify before impeachment investigators; president has ordered staffers not to cooperate with probe

Some Trump allies looked to discredit decorated officer Alexander Vindman, a Jewish Soviet immigrant, questioning his loyalties as he was born in the region

Lt. Col. Alexander Vindman, who was on the call when Trump demanded Ukraine's president investigate political rival Joe Biden, says he 'did not think it was proper'

Charles Kupperman explains he is waiting for 'judicial clarity' on whether he should obey Congress or the president

For beleaguered US president, facing impeachment and criticized over Syria pullout, raid that killed Islamic State leader couldn't have come at a better time

Hitting back, press secretary says John Kelly was 'totally unequipped to handle the genius of our great President'

Lawyers for former national security adviser speaking to three Democratic-led House committees about potential deposition, according to US media

In a ruling that affirms the legality of the impeachment inquiry itself, judge orders department to turn over secret grand jury testimony by October 30

Revelation likely worrying to Trump as it comes amid a House impeachment inquiry into whether he withheld military aid to Ukraine in exchange for dirt on Joe Biden