Mexican President Andrés Manuel López Obrador announced Sunday evening that he's tested positive for COVID-19.

Driving the news: López Obrador tweeted that he has mild symptoms and is receiving medical treatment. "As always, I am optimistic," he added. "We will all move forward."

For the record: The president has been criticized for his handling of the pandemic, which has claimed the lives of nearly 150,000 people and infected over 1.7 million in Mexico, per Johns Hopkins.

Worth noting: López Obrador has downplayed wearing masks, telling reporters last July: "You know when I'm going to put on a mask? When there is no corruption. Then I'll put on a mask and I’ll stop talking."

• He has also labeled lockdowns and face-mask mandates tactics of "dictatorship."

Editor's note: This article has been updated with new details throughout.