President Mnangagwa has sent a message to British Prime Minister Boris Johnson wishing him a speedy recovery following his admission into the Intensive Care Unit on Monday.
PM Johnson tested positive to Covid-19 last week and his symptoms "worsened" on Monday according to the BBC.
In his letter to the UK Prime Minister dated April 7, 2020, President Mnangagwa said it was his hope that Mr Johnson recovered soon.
President Mnangagwa thanked PM Johnson and the British Government for supporting Zimbabwe financially in the wake of the Covid-19 outbreak.
"I am truly sorry to learn that you have been hospitalised, in the course of fighting coronavirus (Covid-19). On behalf of the Government and people of Zimbabwe, and indeed on my own behalf, I want to extend to you our heartfelt wishes for a speedy recovery," said President Mnangagwa.
"Please allow me, Right Honourable Prime Minster, to take this opportunity to gratefully acknowledge the most generous and very timely assistance that your Government has granted to my Government. The assistance will capacitate us in the battle against Covid-19.
"Accordingly, we express our full appreciation for the 35,4 million pounds availed to help us procure medical personal protective equipment, to be used in implementing measures, specifically targeted at cushioning the vulnerable among us.
"I wish to assure you Sir, that my Government has taken very stringent measures to ensure that your assistance reaches the most-needy among our citizens.
"In wishing you well, Right Honourable Prime Minister, we
express our earnest hope that you will soon be fit, so you may successfully carry out your onerous duties as the leader of Her Majesty's Government.
"Please accept, Right Honourable Prime Minister, the assurances of my highest consideration."
Zimbabwe and Britain are in the process of normalising relations and Zimbabwe had made significant headway in its quest to re-join the Commonwealth.
Meanwhile, PM Johnson has asked Foreign Secretary Dominic Raab to deputise "where necessary".
A No 10 Downing Street statement on Monday read: "Since Sunday evening, the Prime Minister has been under the care of doctors at St Thomas' Hospital, in London, after being admitted with persistent symptoms of coronavirus.
"Over the course of this afternoon, the condition of the Prime Minister has worsened and, on the advice of his medical team, he has been moved to the intensive care unit at the hospital."
It continued: "The PM is receiving excellent care, and thanks all NHS staff for their hard work and dedication."