(Bloomberg) -- Mexican President Andres Manuel Lopez Obrador said he tested positive for Covid-19 Sunday, after a weekend trip that took him to two states amid a record climb in the nation’s cases and deaths in the past week. The 67-year-old president announced his diagnosis in a tweet late Sunday, saying his symptoms were mild and that he’s receiving treatment. He’s also expected to stay on top of the country’s affairs, and will take a scheduled call with Russian leader Vladimir Putin on Monday. The peso was little changed against the dollar in Asia trading.“As always, I am optimistic,” he said. “We will all move forward.”Lopez Obrador, known as AMLO, has generally held a lax approach to the virus, refusing to impose mandatory lockdowns and pressing hard to keep the economy open for business. With the increase in deaths in the past week, the nation now has the fourth-highest number of fatalities globally, after the U.S., Brazil and India.Mexico doesn’t have a vice president. The interior minister would assume power for up to 60 days if a president dies, until lawmakers appoint an interim leader. Interior Minister Olga Sanchez Cordero will serve as AMLO’s deputy at his daily press conferences while he recovers, the president tweeted.AMLO suffered a heart attack in 2013, which he has said was caused by arterial hypertension. He first exhibited mild Covid symptoms on Sunday and is now in the care of Health Minister Jorge Alcocer, according to Jose Luis Alomia, a ministry official.Lopez Obrador has largely refused to wear a mask during the pandemic. When asked by reporters why he was contradicting Mexico City’s guidance on mask-wearing, he replied “everyone is free” at a press conference last month. “If using a mask makes a person feel safer, then go ahead,” he said.Biden CallThe president held a telephone conversation Friday with U.S. President Joe Biden in Monterrey, and also attended events in the state of San Luis Potosi over the weekend. AMLO was pictured during the call at a table next to his Foreign Affairs Minister Marcelo Ebrard and former Chief of Staff Alfonso Romo, all three without masks.This past week, Mexico reported two days of record increases in deaths due to the virus, registering a high on Thursday of 1,803 fatalities. The country reported 1.76 million cases and 149,614 deaths as of Sunday evening. Mexico City hospitals have been almost at full capacity for weeks now, with 89% of beds occupied as of Sunday night.Christmas celebrations are believed to have contributed to the recent surge, while the nation’s vaccination campaign has suffered delays. Meanwhile, the president has pledged government austerity, declining to inject any significant stimulus amid the outbreak.The nationalist leader has kept up a heavy travel schedule during the pandemic and flies economy class. AMLO is known to remain standing for up to three hours daily, as he answers questions at his morning press briefings.AMLO has declined to get vaccinated against Covid-19 until late February, when others in his age group are scheduled for the shots.The president is fighting to keep his working majority in Congress during midterm elections to be held in June. His approval rating has held above 60% during the crisis, even with the virus raging and the economy estimated to have shrunk around 9% in 2020.(Adds detail on mask-wearing, peso and political context.)For more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2021 Bloomberg L.P.