The President paid tribute to the Queen after she died.
CNN reported that it was up to Biden to invite former presidents to the funeral.
Thousands of people are expected to attend the funeral of the Queen.
The Royal Family announced on Saturday that the funeral for Queen Elizabeth II will take place on September 19 but who will make the guest list is still up in the air.
After a 70 year reign, the Queen passed away at the age of 96. King Charles III ascended to the throne after his mother's death.
The public will be able to pay their respects to the Queen's coffin in four days, when it will be put in state in the hall. More than one million people are expected at the event.
The funeral service is expected to be held at the abbey where the Queen was crowned. Europe's royal families and leaders from all over the world are expected at the event.
President Joe Biden said Friday that he would attend the service even though he didn't know much about it. It's not clear whether former US presidents will be on the guest list.
According to CNN, the UK was leaving that to Biden.
According to Jeff Zeleny, CNN's chief national affairs correspondent, Buckingham Palace is leaving it up to each country.
There is a procedure for having US presidents invite other presidents. It's possible that President Biden will invite Donald Trump on Air Force One. I don't think that will happen, but I do think that there will be some kind of bipartisan delegation.
Donald Trump was a big fan of the Queen, who he met on several state visits while he was president. Trump paid homage to the Queen in a series of posts on Truth Social after she died.
"Melania and I will always treasure our time with the Queen, and never forget her generous friendship, great wisdom, and wonderful sense of humor" He wrote "May God bless the Queen, may she reign forever in our hearts, and may God hold her and Prince Philip in good health."
During their visits, Trump and the Queen smiled at each other.
After the president's address on September 1 in which he said "MAGA Republicans" was a danger to American democracy, the relationship between Trump and Biden may be more hostile than ever.
CNN's Jake Tapper thinks it would be a clever move for the president to invite him to the funeral if Biden did not.
"I don't think former President Trump would want to be a part of Air Force One, and I think he would prefer his own plane," Tapper said.
Business Insider has an article on it.