House Intelligence Committee Chair Adam Schiff said both Congress and the American people are "being deprived" of US Ambassador Gordon Sondland's testimony today.
Earlier today, Sondland's lawyer said the Trump administration's State Department ordered him not to appear before Congress.
Schiff said Sondland has "text messages or emails on a personal device" the committee would like to see.
"Although we have requested those from the ambassador, and the State Department is withholding those messages as well," Schiff said. “Those messages are also deeply relevant to this investigation and the impeachment inquiry.”
"The failure to produce this witness, the failure to produce these documents we consider yet additional strong evidence of obstruction of the constitutional functions of Congress.