WASHINGTON -- The US General Services Administration (GSA) on Monday ascertained Joe Biden and his running mate, Kamala Harris, as the apparent winners of the US presidential election, Biden's transition team said.

"The GSA Administrator has ascertained President-elect Joe Biden and Vice President-elect Kamala Harris as the apparent winners of the election, providing the incoming administration with the resources and support necessary to carry out a smooth and peaceful transfer of power," the transition team said in a Twitter post.

"Today's decision is a needed step to begin tackling the challenges facing our nation, including getting the pandemic under control and our economy back on track," it added.

The announcement came shortly after President Donald Trump said he has instructed GSA Administrator Emily Murphy to do "what needs to be done with regard to initial protocols."

Without the GSA's ascertainment, Biden has been without transition funds and other support that include security and other policy briefings from government agencies.

Trump still refused to concede, also claiming that his ongoing legal battles will prevail.

In the latest move to show his determination to tackle issues facing the US from Day One, Biden named his picks for top security officials earlier in the day, including former Deputy Secretary of State Antony Blinken tapped as state secretary.

"In the days ahead, transition officials will begin meeting with federal officials to discuss the pandemic response, have a full accounting of our national security interests and gain complete understanding of the Trump administration's efforts to hollow our government agencies," the statement from the Biden-Harris transition team said.

Biden and Vice President-elect Harris will be inaugurated on Jan. 20. (Yonhap)