WASHINGTON

US President Joe Biden will hold what may be the most consequential news conference of his decades-long political career on Thursday as he faces intense and growing Democratic pressure to bow out of the White House race. 

The news conference will serve as the capstone event of the NATO leader-level summit in Washington where the US president has been hosting his counterparts from the 32-nation alliance.

Democratic calls have grown in the last two weeks for Biden to step aside and allow somebody else to become the party's 2024 presidential nominee after he badly fumbled a nationally televised debate against former President Donald Trump in late June.

In all, nine Democrats from the House of Representatives have urged the president to withdraw. Peter Welch became the first Democratic senator to join the chorus Wednesday when he penned a Washington Post op-ed that said, "We cannot unsee President Biden’s disastrous debate performance."

"We cannot ignore or dismiss the valid questions raised since that night," he said. “I understand why President Biden wants to run. He saved us from Donald Trump once and wants to do it again. But he needs to reassess whether he is the best candidate to do so. In my view, he is not.”

Biden and his officials have maintained that he will not step aside and is in the presidential race for the long haul.

The president told congressional Democrats in a letter Monday that he will continue his reelection bid despite the calls for him to withdraw.

"I want you to know that despite all the speculation in the press and elsewhere, I am firmly committed to staying in this race, to running this race to the end, and to beating Donald Trump," he said.​​​​​​​