Republicans believe they now have the votes to block Democrats' demands to bring new witnesses in the impeachment trial against President Donald Trump in the U.S. Senate.

The news came after a meeting between Senate Majority Leader Mitch McConnell (R-Ky.) and centrist Republican Sen. Lisa Murkowski of Alaska.

Democrats were hoping that moderate centrist Republicans like Murkowski might vote with them to call new witnesses, including John Bolton, the former national security adviser to Trump.

On Wednesday, those hopes appeared to be canceled.

"We're going to get it done by Friday, hopefully," said Sen. Mike Rounds (R-S.D.).

"I think I can say the mood is good," agreed Sen. Mike Braun (R-Ind.). "If I had to guess, no witnesses. We'll be in a place where I think everyone is going to have their mind made up and I believe that we'll be able to move to a verdict, and the witness question will be clear at that point."

Bolton reportedly wrote in an upcoming book that he had concerns about personal favors that the president made to foreign leaders of Turkey and Russia. He also reportedly made claims that Trump withheld military aid to Ukraine for the express purpose of pressuring Ukraine to investigate Joe Biden and his son.

Democrats hoped that Bolton's testimony would bolster their accusations in the two articles of impeachment against the president, especially that of abuse of power.

If Republicans are successful in denying Democrats' motions to bring new witnesses, the impeachment trial of Trump could be ended as soon as Friday.

Here's the latest about the trial: