Heathrow passenger numbers fell by 91% in February to below 500,000 – the lowest since 1966.
The London hub blamed decline on the ban on all but essential travel, blanket quarantine, pre-departure and post-arrival testing.
Transatlantic traffic to and from North America saw the steepest fall at 96% followed by Latin America at 95% and the European Union at 93%.
“We are now preparing to restart operations safely, working with all companies across the airport,” a statement by the airport said.
“Our biggest single concern is the ability of Border Force to be able to cope with additional passenger numbers, given recent unacceptable queue times.”
Heathrow is working with the government’s new Global Travel Taskforce to facilitate the safe restart of international travel after May 17.
“The aim should be to simplify and standardise the checks that are required, with a goal of returning to travel as it used to be,” the airport said.
Heathrow chief executive John Holland-Kaye said: “Aviation has always led the UK economy out of recession, and we will do so again.
“The PM’s Global Travel Taskforce can lead the way on reopening international travel and trade safely – but ministers must get a grip of Border Force’s performance so that visitors get a warm welcome to Britain, not a six hour queue.”
The airport added that the Civil Aviation Authority “has acknowledged that Heathrow’s regulatory settlement needs to be adjusted” and it expects a decision in the coming weeks.
It called for an adjustment “which will help keep prices competitive and unlock investment in consumer service and resilience”.