Biden, 81, glares into the teleprompter and almost makes disastrous slip-up during NATO speech to world leaders trying to prove he is fit to serve

President Joe Biden avoided a near disastrous slip-up during his welcome speech to NATO leaders on Tuesday as the eyes of the world watched him to judge his fitness to serve four more years in the White House.

The president, visibly reading from the teleprompter, read a three-word instruction to himself as he awarded the Presidential Medal of Freedom to NATO Secretary-General Jens Stoltenberg - but was saved from utter embarrassment by the audience applause. 

'Ask the military aide,' Biden said while preparing to award Stoltenberg the nation's highest civilian honor.

Biden then quickly caught himself, while the crowd drowned up the flub with cheers. 

'Military come forward,' he said. He proceeded to award the medal, hanging it around Stoltenberg's neck, without incident.

Biden faces a test of his stamina with the start of the NATO summit on Tuesday, where voters in America and leaders from abroad will be watching how he holds up after his car-crash debate with Donald Trump.

The president attempted to reassure the public during a recent interview with George Stephanopoulos on ABC News. Biden sounded raspy as he insisted his poor debate performance was due to a simple cold.

At one point during the Stephanopoulos interview, Biden said he couldn't remember whether he even watched the debate performance after it took place.

'I don't think I did, no,' Biden stated. 

A strong performance at the NATO summit will result in a sigh of relief from allies worried a Trump victory could lead to a return of U.S. isolation. A mistake will send their blood pressure skyrocketing. 

The three-day fitness test began Tuesday evening when Biden, 81, marked the 75th anniversary of the organization. It will continue through meetings and a dinner with world leaders on Wednesday and accumulate in a press conference on Thursday. 

Biden's speech was relatively error free and his words were strong but his focus remained on the teleprompter before him.

He also had a minor stumble when he tried to tell a story about asking Stoltenberg to stay on as NATO chief.

'I realized I was talking to your wife. I personally asked you to extend your service,' Biden said and he then chuckled. 'Forgive me. You put your own plans on hold. You didn't hesitate.'

Biden, last year, asked Stoltenberg to spend another year on the job, which he agreed to do. Dutch Prime Minister Mark Rutte, voted on by NATO leaders, will succeed him, taking over on October 1st. 

The theme of the welcome ceremony was the importance and strength of NATO. 

In his remarks, Biden noted that 'today NATO is more powerful than ever: 32 nations strong.' Sweden and Finland joined the group last year.

But Biden also issued a word of warning about the threat of autocrats. His warning comes as his fellow NATO leaders are worried about the possibility of Donald Trump winning the 2024 presidential election.

'Autocrats have overturned global order,' he noted.

Biden has made 'restoring America's place in the world' a major policy platform after Donald Trump's years of isolationist policy. 

'Remember, NATO's character is fundamentally democratic. Always has been and always must continue to be today. NATO is better resource than it ever has been,' he said in his remarks. 

Trump has suggested that in a second term he would not defend NATO allies who didn't pay their full dues - 2% of their respective GDP. The former president also has questioned the amount of aid to the Ukraine.

Both of these prospects have made NATO leaders uneasy.

Biden noted that he has gotten more NATO members to increase their dues.

'The year 2020 year was the year I was elected president. Only nine NATO allies are spending 2% of their defense GDP,' he said. 'This year 23 will spend at least 2%.'

'And some will spend more than that. And the remaining countries that have not yet reached that milestone will get there. This is remarkable progress. Proof our commitment is broad and deep.'

Biden also announced the U.S. and additional NATO allies will send Ukraine dozens of air defense systems in the coming months, including at least four of the powerful Patriot systems that Kyiv has been seeking. 

'Russia will not prevail,' the president said.

'Ukraine can and will stop Putin,' Biden noted.

The U.S., Germany and Romania will send Ukraine additional Patriot batteries, while the Netherlands and others will provide Patriot components to make up one more battery. Italy will provide a SAMP-T air defense system.

Other allies, including Canada, Norway, Spain and the United Kingdom, will provide a number of other systems that will help Ukraine expand its coverage. Those systems include NASAMS, HAWKs, IRIS T-SLM, IRIS T-SLS and Gepards. And other nations have agreed to provide munitions for those systems.

Biden will meet with Ukrainian President Volodymyr Zelensky on Thursday on the sidelines of the NATO summit. 

The welcome ceremony on Tuesday began with a video on the history of the alliance and the important role it has planned in Europe in the last 75 years with the narrator calling it 'the most powerful alliance in human history.'

The video touched on the fall of the Berlin Wall and the September 11th attacks.  

'True friendship is more than a promise more than just signatures on a piece of paper. It's a way of navigating life and when you show yourself as worthy of true friendship, it draws others with that same sense of commitment to your side,' the narrator said.

Members of the military sang a melody of and war songs. All the flags of the NATO nations were on display. And a chorus of bugles played the leaders out. 

The White House brought in Hollywood heavyweights Ron Howard and Brian Grazer to produce the event, which featured the music of famous composer Hans Zimmerman.

The gathering of the leaders from the 32 NATO countries — plus Pacific partners Australia, Japan, New Zealand and South Korea, as well as Ukraine — is expected to be one of Biden's last appearances at an international forum before Election Day.

It also comes before the Republican National Convention in Milwaukee next week. 

But, in a reminder of his age, Biden is the only head of government who was alive during NATO's founding.