It comes amid bombshell allegations from Bolton that are reportedly revealed in a draft of his upcoming book.
According to The New York Times, the book’s manuscript describes how the US president told Bolton he wanted to continue freezing security assistance to Ukraine until officials helped with investigations into Democrats including the Bidens.
The allegations counter Trump’s claim that the hold-up of aid was separate to the president’s requests for Ukraine to investigate his political rivals.
Trump has denied Bolton’s claims, saying they were made “only to sell a book”.
https://twitter.com/realDonaldTrump/status/1221663764031905793
Pressure is mounting on Republicans to call Bolton as a witness in the Senate impeachment trial after the manuscript leaked.
Key Republican senators have indicated they are likely to join Democrats and vote to subpoena Bolton to testify.
Maine senator Susan Collins said the reports regarding Bolton’s book “strengthen the case for witnesses and have prompted a number of conversations among my colleagues”.
Meanwhile, Utah senator Mitt Romney said it was becoming “increasingly apparent that it would be important to hear from John Bolton”.
“I think it’s increasingly likely that other Republicans will join those of us who think we should hear from John Bolton,” he said.
“I’ve spoken with others who’ve opined upon this as well.”
South Carolina senator Lindsey Graham, one of Trump’s key allies, also said he would support a subpoena to obtain Bolton’s manuscript.
Senator Pat Toomey of Pennsylvania has reportedly pushed to have two witnesses testify – one called by the Democrats and one by Republicans.
Democrats need four Republican votes to call witnesses.
Bolton has said he would appear before the Senate if served a subpoena.
Republican Senate leaders have thus far resisted calls for witnesses so as to swiftly acquit Trump and keep him in office.
