US President Joe Biden and his Republican rival Donald Trump faced off in the first debate of the 2024 presidential election on Thursday night.

Millions of Americans had been expected to tune into the 90-minute debate hosted by CNN in Atlanta.

Biden opened the debate by blaming Trump for "an economy that was in free fall" when he took over and a pandemic that "was so badly handled, many people were dying."

Trump hit back by attacking the Biden administration's record.

"He has not done a good job. He's done a poor job. And inflation is killing our country. It is absolutely killing us," Trump said.

Trump relatedly made claims of being the "best" in a number of areas, without providing evidence. "Donald Trump broke the fact-check machine more than I can count tonight," said CNN anchor David King.

Biden meanwhile gave an uneven performance, delivering answers with a raspy voice and at times appearing to lose his train of thought. "Biden's answers were, in a lot of cases, not coherent," CNN anchor Abby Phillip added.

Biden, Trump clash over Gaza and Ukraine

Foreign policy discussion focused largely on the wars in Gaza and Ukraine.

Trump claimed that Washington's support for Ukraine was hurting the economy.

"This is a war that never should have started. If we had a leader in this war... He's given $200 billion now or more to Ukraine, he's given $200 billion. That's a lot of money. I don't think there's ever been anything like it," Trump said.

But Biden hit back that the military aid to Ukraine was delivered in the form of US-made weapons, and that other Western nations have collectively put forward similar amounts of aid.

"This is a guy who wants to pull out of NATO," Biden said, adding that he "got 50 other nations" to support Ukraine against Russia's invasion.

Advanced age in the spotlight

Biden and Trump were, respectively, the oldest and second-oldest presidents to ever be elected. Both of them were questioned about their fitness to be president for the next four years.

Biden, who spoke with a hoarse voice throughout the debate, mentioned that he became one of the youngest senators when he entered Congress.

He went on to tout a list of his achievements as president and noted that Trump is only "three years younger."

In his retort, Trump claimed to have easily passed cognitive tests and challenged Biden to do the same. 

He also bragged about his golfing prowess and said he's in as good a shape as he was 25 years ago and perhaps "even a little bit lighter."

Biden says Trump has 'morals of an alley cat'

Biden slammed his opponent over the historic 34 felony convictions arising from payments made to keep an alleged extramarital affair with a porn star out of the public eye in his first run for the White House.

"The only person on this stage that's a convicted felon is the man I'm looking at right now," Biden said, referring to Trump. He also said Trump had "the morals of an alley cat."

Trump deflected by referring to Hunter Biden as a "convicted felon." He evoked retribution by claiming, without evidence, that Biden could face charges "when he leaves office."

"Joe could be a convicted felon with all the things that he's done," Trump said. Biden is not facing any felony charges.

A close race

Thursday's debate was one of just two between the two major contenders who have been polling closely for months.

"Neither candidate can afford to lose this first debate," DW's Washington correspondent Ines Pohl said.

Uniquely, the debate was held without a studio audience, and with microphones that producers can switch off to stop the candidates speaking over one another.

The debate also took place early, before either party holds their congress where they are all but certain to name Biden and Trump as their official presidential candidates.

What are the issues?

The sitting and former presidents clashed on reproductive rights and illegal immigration, as well as the wars in Gaza and Ukraine.

The 81-year-old Biden came into the debate amid speculation about his mental sharpness, and whether he will be able to guide the country amid multiple world crises.

Meanwhile, 78-year-old Trump has attracted attention over his recent felony conviction, while he aims to convince millions of Americans that he is suitable to be president again.

"In normal election years, the winner is determined by their ability to convincingly sell their political agenda. This year people seem to be more focused on who will make the most mistakes and provide better fodder for internet memes," DW's Pohl said.

Trump enjoys a modest enthusiasm advantage compared to Biden.

According to a new AP-NORC poll, 6 in 10 Republicans are extremely or very satisfied with Trump, compared to about 4 in 10 Democrats who say they're satisfied with Biden.

The latest Quinnipiac University poll also has Trump polling at 49% nationwide, compared to Biden's 45%.

zc/ab (AP, AFP, Reuters)