Drew Angerer/Getty Images President Donald Trump shakes hands with Sen. Lindsey Graham (R-SC) during an event about judicial confirmations in the East Room of the White House on November 6, 2019

Trump ally Sen. Lindsey Graham said on Fox News that former national security adviser John Bolton should talk – but at a news conference.

Graham told Fox News’ Martha MacCallum that he has “all the evidence I need,” before adding that he thinks the impeachment trial “needs to end now.”

Bolton could be a key witness in the impeachment trial, if the Senate votes to allow witnesses to testify.

Revelations leaked from an unpublished manuscript of his upcoming book led to bombshell report in The New York Times seemingly confirming that Trump withheld military aid to Ukraine in exchange for investigations of a political rival.

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Trump ally Sen. Lindsey Graham encouraged former national security adviser John Bolton come forward and share what he knows – at a news conference.

In an interview with Fox News’ Martha MacCallum on Tuesday, the senator said Bolton had “thrown the country into a ditch here,” adding that the former national security adviser should “just come forward and say what’s on your mind.”

“Hold a news conference, and we’ll consider what you’ve got to say if you think is that important,” Graham told Fox News.

“So I just think this, to me, needs to end,” Graham added. “It needs to end now.”

Graham said he thinks the Senate has all the evidence it needs, and lambasted House Democrats for withdrawing their subpoena Bolton’s deputy Charles Kupperman to testify in the impeachment hearing. Kupperman filed a lawsuit asking a judge whether he had to appear, after he was told to ignore the subpoena by the White House. The House withdrew its subpoena, not wanting to delay the impeachment inquiry with a legal battle.

Bolton is represented by Kupperman’s lawyer and indicated at the time that he would follow the same process if subpoenaed.

Revelations leaked from an unpublished manuscript of Bolton’s upcoming book published in a bombshell New York Times report seemingly confirmed a quid pro quo with regards to military aid for Ukraine and bolstered Democrats’ calls for witnesses, which GOP leadership has indicated they don’t want to call.

Bolton, who has since said he would testify if called, could prove key witness in the impeachment trial – if the Senate votes to allow witnesses.

Senate Majority Leader Mitch McConnell said earlier Tuesday that he doesn’t have enough votes to block witnesses.

On Tuesday, when asked by MacCallum about calling witnesses, he said that if Bolton was called, he’d call former Vice President Joe Biden and his son Hunter Biden, and he warned that the process would drag on.

The president also weighed in on Bolton’s book with a tweet on Tuesday night.

“Why didn’t John Bolton complain about this ‘nonsense’ a long time ago, when he was very publicly terminated,” Trump wrote. “He said, not that it matters, NOTHING!”

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