Joe Biden has said that he and his wife "send their thoughts" to Donald Trump and First Lady Melania, wishing them a "swift recovery".
The Democratic nominee joins a host of world leaders and politicians who have sent messages of support to the couple.
Mr Biden said in a tweet: "Jill and I send our thoughts to President Trump and First Lady Melania Trump for a swift recovery.
"We will continue to pray for the health and safety of the president and his family."
It comes after the US President and the First Lady tested positive for coronavirus.
Mr Trump tweeted on Thursday: "Tonight, @FLOTUS and I tested positive for COVID-19. We will begin our quarantine and recovery process immediately. We will get through this TOGETHER!"
Mr Biden's message of support come in the wake of the first presidential debate on Tuesday where the two rivals interrupted and hurled insults at each other.