“Wishing my friend @POTUS @realDonaldTrump and @FLOTUS a quick recovery and good health,” Indian Prime Minister Narendra Modi said on Twitter.
"My best wishes to President Trump and the First Lady. Hope they both have a speedy recovery from coronavirus," added British Prime Minister Boris Johnson, who went through a harrowing ordeal with the disease earlier this year.
Benjamin Netanyahu, the prime minister of Israel, said he and his wife were thinking of the Trumps and "wish our friends a full and speedy recovery."
Netanyahu was among those who attended an outdoor White House signing ceremony on Sept. 15. Israel signed peace accords with the United Arab Emirates and Bahrain. Officials from the countries said the deals were assisted greatly by Trump.
Russian President Vladimir Putin said in a statement that he's pulling for a quick recovery for Trump and his wife.
"I am certain that your inherent life energy, high spirits and optimism will help you to overcome the dangerous virus," Putin said in a statement released by the Kremlin on Friday.
A spokesman for German Chancellor Angela Merkel said she sends her best wishes to the Trumps.
"I hope that they recover well from their coronavirus infection and are soon completely healthy again," the spokeswoman quoted Merkel as saying, Reuters reported.
Taiwan's Ministry of Foreign Affairs said in a statement that officials were sending their best wishes to the Trumps "for a speedy recovery & return to full health," adding: "The government & people of Taiwan stand with the U.S. at this testing time."
Vice President Mike Pence said he and his wife were sending their "love and prayers" to the president and first lady.
"We join millions across America praying for their full and swift recovery. God bless you President Trump & our wonderful First Lady Melania," he wrote on Twitter.
It wasn't clear whether Pence would be or has been tested for COVID-19 following the Trumps' diagnosis, or the confirmed case of White House aide Hope Hicks. The White House didn't respond to an inquiry.
While there were fears that Trump, 74, is in a high-risk group for COVID-19, former White House physician Ronny Jackson, now a Republican candidate for a congressional seat, said early Friday that both Trumps are not showing symptoms.
"The President is in very good health and has NO comorbities [sic]," he wrote on Twitter, referring to underlying health conditions such as diabetes or obesity.
"Well over 99% of healthy individuals in the President’s age group recover completely and most never even become symptomatic. I fully expect this to be the case with President Trump as well," he added.
Members of Congress joined world leaders in wishing the Trumps well.
"My husband Abraham and I offer our best wishes and aloha to President @realDonaldTrump and the First Lady @FLOTUS and praying for their speedy recovery," Rep. Tulsi Gabbard (D-Hawaii) wrote on Twitter.
"We also send our best wishes to Ivanka, Tiffany, Donald Trump Jr., Eric, and Barron during this difficult time."