The number of people infected with the novel coronavirus globally has exceeded 4 lakh while over 21,000 people have died.
"We understand that these countries are now trying to assess when and how to ease these measures", Tedros said at a press briefing.
Tedros said he and Trump had recently spoken and that the president is "doing all he can". Because fighting this pandemic needs political commitment and commitment at the highest level possible.
Director-General Dr Tedros Adhanom Ghebreyesus revealed the six key actions that nations must undertake to fight COVID-19.
He added that wide-scale efforts to slow the coronavirus should have started weeks ago. "We had been saying to the world the window of opportunity is narrowing and the time to act was actually more than a month ago, two months ago". But on their own, these measures will not extinguish epidemics.
He added: "Asking people to stay at home and shutting down population movement is buying time and reducing the pressure on health systems".
Ghebreyesus then called on governments to listen to the elderly, those most at risk from COVID-19.
The global death toll has reached 16,231, of which more than 10,000 deaths have been in Europe. "The question is how a large price we will pay".
The summit, which will be chaired by Saudi Arabia's King Salman bin Abdulaziz Al Saud, aims to "advance a coordinated global response to the COVID-19 pandemic and its human and economic implications", according to the statement published by the G20 Secretariat on Tuesday.
"This is especially relevant for many vulnerable countries whose health systems may collapse under the weight of the numbers of patients we've seen in some countries with community transmission".