Before Nancy Pelosi landed in Taipei for a controversial meeting with President Tsai Ing-wen, the White House was careful to emphasize that the Speaker of the House of Representatives makes her own decisions.

But behind the scenes, officials in US President Joe Biden's administration were outraged by her insistence on using the trip as a cornerstone for her career at a time of very delicate relations with Beijing.

According to people familiar with the conversations, in an attempt to quietly convince Pelosi to postpone the visit, the White House sent senior members of the National Security Council, as well as State Department officials, to inform the speaker and her team about the geopolitical risks.

When it became clear that Pelosi was not amenable to influence, the administration instead planned unforeseen circumstances, organizing a scramble to ensure the functioning of communication channels with Beijing and minimize any consequences.

The failure to convince Pelosi to postpone is another complication for an administration that is still figuring out its approach to China. And this put Biden's officials in an awkward position when they were sidelined by one of the most influential speakers of the House of Representatives in our time, who has never shied away from poking at China, and is not afraid to upset anyone who gets in her way.

According to a State Department official, when Chinese officials in Beijing summoned the U.S. ambassador to express an official protest, Nicholas Burns confirmed that the Biden administration wanted to avoid any escalation and intended to keep all lines of communication open.

Pelosi's trip came as she is expected to soon end her historic career as the first female speaker of the House of Representatives. Although she is likely to be re-elected to her House seat in San Francisco, Republicans seem poised to grab a majority in the House, and Pelosi struck a deal in 2018 with younger House members agreeing to term limits.

Pelosi, 82, appreciated her members' caution about the trip and was particularly unhappy with leaks her team believed came from the Biden administration in an attempt to force her to cancel the visit, people familiar with the matter said.

A spokeswoman for the NSC said that the allegations that the administration intentionally leaked information are false. NSC spokesman John Kirby on Tuesday called them "unfortunate," noting that the speaker should be able to travel on her own terms.

Information about the visit was carefully hidden even from the lawmakers who accompanied Pelosi. They did not receive the full itinerary of the trip, including confirmation of a stop in Taiwan, until the day of their departure and only after the delegation boarded the plane.

The trip was originally scheduled to take place in April, but was postponed when Pelosi tested positive for Covid-19. Pelosi's office continued to clarify to members who were supposed to be on this trip that it was just postponed.

Communication between the speaker's team and the White House was tense, and tensions intensified when Biden told reporters in late July that the US military was against Pelosi's then unconfirmed plans for the trip.The more the administration tried to influence behind the scenes, the more Pelosi gathered her courage..

At one point, her team suggested that she might consider postponing the trip if the president publicly asked her to do so. Biden's advisers didn't believe it was a good idea, not least because they weren't sure she would comply, people familiar with the exchange said.

On Tuesday, as she landed and China threatened military exercises around the island, Kirby repeated his warnings and said the U.S. was ready to handle whatever Beijing decides to do in response.

The White House declined to say whether the president personally supported the speaker's trip and whether he believes that it contributes to the goals of US foreign policy.

Biden this year said he would support military intervention if China invaded Taiwan - a comment that was quickly refuted and clarified by his advisers. However, people familiar with the internal discussions said that the president probably expressed his opinion then, stressing that this would not affect the long-standing "One China" policy in any way.

U.S. officials have spent the last 19 months carefully trying to rebuild relations with China, avoiding the unpredictability of the Trump administration. They stressed the need for clear communication to avoid unintended consequences or misunderstandings that could lead to conflict.

In less than 24 hours on the ground, Pelosi also met with human rights activists and business leaders. According to her, her message was unwavering support for Taiwan in the face of Beijing's threats.

The trip was in keeping with her political brand, which she built on her steely determination to stand up to China. Throughout her career, she has taken a tougher stance on China than virtually any of the U.S. presidents she has dealt with.