(CNN) — The General Services Administration has informed President-elect Joe Biden that the Trump administration is ready to begin the formal transition process, according to a letter from Administrator Emily Murphy sent Monday afternoon and obtained by CNN.

The letter is the first step the administration has taken to acknowledge President Donald Trump’s defeat, more than two weeks after Biden was declared the winner in the election.

Murphy said she had not been pressured by the White House to delay the formal transition and did not make a decision “out of fear or favoritism.”

“Please know that I came to my decision independently, based on the law and available facts,” Murphy wrote. “I was never directly or indirectly pressured by any Executive Branch official — including those who work at the White House or GSA — with regard to the substance or timing of my decision. To be clear, I did not receive any direction to delay my determination.”

The letter marks Murphy’s formal sign off on Biden’s victory, a normally perfunctory process known as ascertainment. The move will allow the transition to officially begin, permitting current administration agency officials to coordinate with the incoming Biden team, and providing millions in government funding for the transition.

The Biden team has not waited for the formal transition process to begin preparing for the presidency, as Biden announced several Cabinet picks on Monday. But the delay in ascertainment meant that Biden’s team was locked out from government data and could not make contact with federal agencies, nor could it spend $6.3 million in government funding now available for the transition. A Biden official said the most urgent need was for the transition to be given access to Covid-19 data and the vaccine distribution plans.

The Biden team will now have access to additional office space inside the agencies and the ability to use federal resources for background checks on Biden’s White House staff appointments and Cabinet picks.

READ: GSA letter to Biden stating that transition can formally begin

Yohannes Abraham, executive director of Biden’s transition, said the start of the transition was a “needed step to begin tackling the challenges facing our nation, including getting the pandemic under control and our economy back on track.”

“This final decision is a definitive administrative action to formally begin the transition process with federal agencies,” Abraham said. “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 out government agencies.”

The ascertainment letter was sent Monday after Michigan formally certified its election results earlier in the day and more Trump lawsuits were dismissed. Georgia certified its razor-thin presidential results on Friday, and Pennsylvania is nearing certification of its election results, too.

It’s the latest sign that Trump’s conspiracy-laden legal bid, led by Rudy Giuliani, to circumvent the outcome of the election is nearing an end. The Trump campaign’s lawsuits to delay certification of the election have been dismissed in multiple states, as his legal team has failed to provide any evidence of widespread voter fraud.

But until now, Murphy had refused to move forward with the ascertainment process, despite Biden’s clear victory. Murphy, a Trump political appointee, has faced intense scrutiny and political pressure from Democrats and, in recent days, Republicans calling for the start of a smooth transition. In a statement Monday, Sen. Rob Portman, an Ohio Republican, said that “there is no evidence as of now of any widespread fraud or irregularities that would change the result in any state” and called on the transition process to begin.

In the letter, Murphy suggested that the ascertainment rules were vague and should be updated.

“GSA does not dictate the outcome of legal disputes and recounts, nor does it determine whether such proceedings are reasonable or justified,” she wrote. “These are issues that the Constitution, federal laws, and state laws leave to the election certification process and decisions by courts of competent jurisdiction. I do not think that an agency charged with improving federal procurement and property management should place itself above the constitutionally-based election process. I strongly urge Congress to consider amendments to the Act.”

Trump tweeted moments after the letter was reported, thanking Murphy for her work and affirming the decision to start the transition.

“I want to thank Emily Murphy at GSA for her steadfast dedication and loyalty to our Country. She has been harassed, threatened, and abused — and I do not want to see this happen to her, her family, or employees of GSA. Our case STRONGLY continues, we will keep up the good fight, and I believe we will prevail!” Trump tweeted. “Nevertheless, in the best interest of our Country, I am recommending that Emily and her team do what needs to be done with regard to initial protocols, and have told my team to do the same.”

Two Trump advisers said the President’s tweets are being read by people in his orbit as essentially a concession.

“A veiled attempt to justify continued fundraising solicitations,” the second adviser said.

The General Services Administration informed federal departments on Monday night that it has ascertained Biden to be the winner of the presidential election, according to an email obtained by CNN.

“In accordance with the Presidential Transition Act of 1963, as amended, today, November 23, 2020, the GSA Administrator has ascertained Joseph R. Biden and Senator Kamala Harris the apparent successful candidates for the offices of President and Vice President, respectively,” Mary Gibert, the federal transition coordinator, wrote in an email to federal department contacts.

A senior White House official said some staffers were initially caught off guard by the GSA letter, learning about it first from CNN. But the official said staffers will begin to cooperate with the Biden transition team, adding that they were seeking more information on next steps.

For two weeks after the election was called for Biden, Murphy was silent as the ascertainment delay dragged on, sparking public pressure from congressional Democrats and Biden himself, who warned that the delay could cost lives due to the Covid-19 pandemic.

Democrats were demanding a briefing from Murphy on Tuesday to explain her decision-making, rejecting the GSA’s proposal earlier Monday for her deputy to brief Congress next week. Democratic committee chairmen sent a slew of new letters to Murphy on Tuesday demanding she allow the transition to begin and warning of the consequences for failing to do so.

This story has been updated with additional reporting on Monday.

CORRECTION: An earlier version of this story misspelled Mary Gibert’s name.

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