Biden also urged Mueller not to being his probe to an "arbitrary" end before the crucial midterms.
"I think it should be issued when they finish the investigation", Biden answered simply. I've been around a long time. 'You wait until the investigation's finished. You wait until it's finished.
'I think we should focus on all the bad things that are happening now in terms of interest of the middle class people and working class people, ' Biden added. "Let's see where the investigation takes us".
May lobbies European leaders for Brexit deal
International Development Secretary Penny Mordaunt told Sky News: "No-one is planning on resigning". Although Barnier said the two sides need "much more time" to work "calmly and patiently" on a deal.
Although Biden has not yet said whether he'll run in 2020, the former vice president and senator would be 77 by the start of the primary contests - and 78 by Inauguration Day in 2021.
'It's totally appropriate for people to look at me and say if I were to run for office again, 'Well God darn you're old, " he said in remarks carried by CNN. "It's a legitimate question, and so I think age is relevant". "Well, chronologically I am old".
Among other big Democrat names seen as potential candidates are populist leftist Bernie Sanders, 77, and media mogul Michael Bloomberg, who is 76. He has been campaigning heavily for midterm candidates in recent weeks alongside former President Barack Obama and has ramped up his attacks on the current White House, saying earlier this month that Trump was "trashing American values". He says he is "100 percent" sure to seek reelection.