However, in a televised address to the nation, Mr Giammattei looked “a bit out of breath”.
“My symptoms are very mild. Up to now, I have body aches, it hurt more yesterday than today, like a bad cold,” the president said.
“I don’t have a fever, I have a bit of a cough.”
“I am busy working from home,” he said.
The 64-year-old has multiple sclerosis and uses canes to walk.
The government press office said in a statement that Mr Giammattei “will be isolating himself from all public activity, and so all communication will be conducted remotely”.
The announcement came on the same day that the country reopened its borders and international flights after a six-month closure due to the coronavirus pandemic.
The country’s Health Ministry said that foreigners seeking to enter Guatemala would have to present a negative PCR test taken at most 72 hours before entry.
Guatemalans returning to their country and children under 10 would not be subject to the test requirement. All those entering or leaving would have to wear face masks.
Guatemala closed its airports and borders with Mexico, Belize, Honduras and El Salvador on March 16.
The country of 16 million people has more than 83,600 confirmed coronavirus cases, and 3,036 deaths.
