Trump impeachment: President tries to undermine claim that witness overheard call with bizarre tweet about phones

David Holmes arrives to give evidence at the impeachment hearings: AP

Donald Trump has tried to undermine claims that a US diplomat overheard him on the other end of a phone call to an ambassador – tweeting a bizarre message while the diplomat was giving evidence at the impeachment hearings.

The president tweeted: "I have been watching people making phone calls my entire life. My hearing is, and has been, great. Never have I been watching a person making a call, which was not on speakerphone, and been able to hear or understand a conversation. I've even tried, but to no avail. Try it live!"

The tweet was sent while David Holmes, a State Department official, was reading his opening statement in the latest public hearings in the impeachment inquiry.

He was appearing alongside Fiona Hill, a British-born expert on Russia.

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