"I've been clear: the United States will respond in a robust and meaningful way if the Russian government engages in harmful activities".
The president also said he will be reassuring allies about the US role in the world.
Tonight it's being reported that the United States is to buy 500 million Pfizer doses to donate internationally. The U.S. has vaccinated more than half of its adult population, but impoverished countries are trailing far behind that level of inoculation.
First Lady Jill Biden gave a brief speech in which she paid tribute to service personnel and their families, then 14-year-old Sydney Glascock, whose mother and father are both service personnel, introduced the president.
Putin is due to meet face-to-face with President Biden in Switzerland next week, and Reuters' Russia Bureau Chief Andrew Osborn surmises the ban is also a brazen message to the USA ahead of the rendezvous - likely something along the lines of "butt out of our politics", he writes.
After the G7, Mr Biden and First Lady Jill Biden will meet the Queen at Windsor Castle before flying to Brussels for talks with North Atlantic Treaty Organisation on Monday and the European Union on Tuesday.
Florida shooting: Three dead, including shooter, at Publix supermarket
A sheriff's office helicopter hovered in the air above the store, and a Palm Beach County Fire Rescue vehicle was at the scene. The company is Florida's largest grocery chain and has more than 1,200 stores in the Southern United States.
Mr Biden, who is also the Commander in Chief, told the troops in the hangar to stand "at ease", quipping: "I keep forgetting I'm president".
The airbase was the first place outside of the United States that Joe Biden has visited since his election victory over Donald Trump last November.
The White House announced that President Biden would attend the G7 Summit in April. And what might this trip reveal about Biden's foreign policy doctrine and what we can expect of USA global standing in the years to come?
Security officers stand outside the Villa La Grange, ahead of the June 16 summit between U.S. President Joe Biden and Russian President Vladimir Putin, in Geneva, Switzerland, June 4, 2021. "Joe Biden is not meeting with Vladimir Putin despite our countries' differences; he's meeting with him because of our countries' differences". Each country has expelled some of the other's diplomats from Moscow and Washington.
"The election of Joe Biden as president has led to a dramatic shift in America's global image".