Republican Sen. Lindsey Graham, chairman of the Judiciary Committee, called on Sunday for the Senate to change the rules set up for impeachment in order to start President Donald Trump's trial within days, even if it means the chamber proceeds without receiving articles of impeachment from the House of Representatives.

"If we don't get the articles this week, then we need to take matters in our own hands and change the rules ... so we can start the trial," Graham said during an interview with Maria Bartiromo on Fox News' "Sunday Morning Futures."

The House voted to impeach Trump on Dec. 18 for abuse of power in pressuring Ukraine to investigate his political opponent and obstructing Congress, making him just the third president in U.S. history to be impeached.

While the Republican controlled Senate seems certain to keep Trump in office, it's unclear when the impeachment trial will begin and how it will proceed.

House Speaker Nancy Pelosi has not yet sent the House's impeachment articles to the Senate or identified the case managers who will act as prosecutors during a Senate trial.

Senate Minority Leader Chuck Schumer, D-N.Y., has argued that witnesses be allowed to testify. Senate Majority Leader Mitch McConnell, R-Ky, said that the trial cannot proceed until it receives the articles of impeachment and argued that the issue of witnesses should be decided later in the trial process.

"What she's doing is bad for the country," Graham said of Pelosi. "It's bad for the Senate. It keeps us from getting on with the business of the American people. It denies the president his day in court."

Once the House transmits the articles of impeachment, decisions about how to proceed with the trial must have 51 Senate votes. It would require 67 votes to convict Trump on the two impeachment charges and remove him from office.