World leaders have reacted to the announcement from United States President Joe Biden that he will no longer seek re-election.
The 81-year-old Democrat and commander-in-chief until his term ends in January 2025.
Biden endorsed vice-president Kamala Harris to replace him as his party's candidate in the November contest against former president and Republican candidate Donald Trump.
Biden wrote that it had been the greatest honour of his life to serve as US president.
"And while it has been my intention to seek re-election, I believe it is in the best interest of my party and the country for me to stand down and to focus solely on fulfilling my duties as President for the remainder of my term."
Biden's announcement against Trump.
What have Australian politicians said?
Australian leaders have thanked Joe Biden for his service and support of the two nations' alliance after the US president withdrew his bid for re-election.
Early on Monday, Prime Minister Anthony Albanese posted a message on X expressing his gratitude to Biden.
"Thank you for your leadership and ongoing service President Biden," Albanese wrote.
"The Australia-US Alliance has never been stronger with our shared commitment to democratic values, international security, economic prosperity and climate action for this and future generations."
Australia's ambassador to the US Kevin Rudd, whose prime ministership fell victim to a leadership spill in 2010, noted the difficulty of Biden's choice.
"Leadership can be a lonely place," he posted on X.
"We can all take pause to recognise and respect the difficult decision President Joe Biden has made today."
Opposition leader Peter Dutton thanked Biden and highlighted the importance of a security alliance between the US, the United Kingdom and Australia that the American president helped launch.
"Like American Presidents before him, Joe Biden has been a leader resolutely committed to the alliance," he posted on X.
"I thank the President for the support and abiding friendship he has shown to Australia.
"In particular, I thank President Biden for launching the defence endeavour of AUKUS which the peoples of our two countries carry forward with energy and determination."
Speaking to ABC this morning, former prime minister Malcolm Turnbull said that Biden had made a "tough" and "brave" decision but said it was "definitely the right decision".
"Biden has had a very, very successful presidency. He's achieved an enormous amount," Turnbull said.
"His biggest vulnerability was his age and perceptions that he ... was no longer up for the job. So he's done the right thing in stepping back and I think that's why it's been universally welcomed."
Former foreign affairs minister Alexander Downer told the ABC it was "slightly shocking" that Biden has pulled out but also "unsurprising".
"Joe Biden had come under enormous pressure, Democrats came to the conclusion he couldn't beat Donald Trump, and he just looked too old for the job," he said.
"I think in the end, he had to — he had to cave in to the huge pressure that was being put on him by his party."
Other reactions from around the world
Newly-elected UK Prime Minister Keir Starmer has commented on Biden's decision on X, saying that he respects Biden's choice and looks forward to working with him for the remainder of his presidency.
"I know that, as he has done throughout his remarkable career, he will have made his decision based on what he believes is best for the American people," Starmer said.
Ukrainian leader Volodymyr Zelenskyy thanked Biden for taking "bold steps" in supporting his country, praising the US president's "tough but strong decision" to end his reelection bid.
In a statement posted to X, Polish Prime Minister Donald Tusk addressed Biden directly, saying the president had made "many difficult decisions thanks to which Poland, America and the world are safer, and democracy stronger".
"I know you were driven by the same motivations when announcing your final decision. Probably the most difficult one in your life," Tusk said.
Israeli President Isaac Herzog posted to X that he wanted to extend his "heartfelt thanks" to Biden "for his friendship and steadfast support for the Israeli people over his decades long career".
Germany's Chancellor Olaf Scholz wrote on X: "Joe Biden has achieved a lot: for his country, for Europe, for the world. Thanks to him, transatlantic cooperation is close, NATO is strong and the USA is a good and reliable partner for us. His decision not to run again deserves respect."
Venezuela's President Nicolas Maduro told Biden "to be at ease with your conscience because you took the sensible and correct decision."
"He prioritised his family, his health and he realised at that age, with failing health, he couldn't take the reins of his country, much less a presidential candidacy," Maduro said.
The reaction from Republicans
As world leaders paid tribute to Biden's performance on the world stage, leading Republicans were insisting he was unfit to remain president.
"If Joe Biden is not fit to run for president, he is not fit to serve as president," said a statement from House Speaker Mike Johnson, the top Republican in Congress.
"He must resign the office immediately. November 5 cannot arrive soon enough," he added.
Former president Donald Trump, the Republican presidential nominee, wrote on his Truth Social network: "Crooked Joe Biden was not fit to run for president, and is certainly not fit to serve."
