WASHINGTON — Senate Republicans and former national security officials Thursday increased the pressure on the General Services Administration to grant President-elect Joe Biden access to presidential-level intelligence briefings, a key step in the transition to the White House.

The congressional Republicans stopped short of acknowledging that President Donald Trump had been defeated, but they acknowledged a need for Biden to begin to get critical information about the country’s security.

Over 150 former national security officials urged the GSA in a letter Thursday to recognize Biden and Vice President-elect Kamala Harris as the winners of the election, giving them access to the President’s Daily Brief and allowing them to begin to obtain the security clearances necessary for members of the transition team.

“In this moment of uncertainty, we must put politics aside,” reads the letter, which was obtained by NBC News.