A motion to allow subpoenas for witnesses and documents in the Senate trial of U.S. President Donald Trump's impeachment failed to pass the Republican-controlled upper chamber on Friday, suggesting a quick end to the proceeding.

The Senate voted 49 to 51 to block the motion.

Two Republicans joined Democrats in requesting witnesses for the impeachment trial but they fell short of a simple majority needed to pass the motion.

The vote came after the House impeachment managers and Trump's defense team debated for hours over whether the Senate should call witnesses on Friday.

It also followed more than a week of arguments from both sides and a questions-and-answers session involving all senators who act as the jury.