WASHINGTON: President Donald Trump said Friday he might attend a rally planned on Saturday in Washington by supporters of his unsubstantiated claim that the US election was rigged against him. “Heartwarming to see all of the tremendous support out there, especially the organic Rallies that are springing up all over the Country, including a big one on Saturday in D.C. I may even try to stop by and say hello,” Trump tweeted. Heartwarming to see all of the tremendous support out there, especially the organic Rallies that are springing up all over the Country, including a big one on Saturday in D.C. I may even try to stop by and say hello. This Election was Rigged, from Dominion all the way up & down! — Donald J. Trump (@realDonaldTrump) November 13, 2020 Trump, who has remained mostly holed up in the White House this week as he stews over his election loss, is set to deliver an update Friday on Operation Warp Speed, the effort to get a coronavirus vaccine to market as speedily and safely as possible. Trump, who was briefed by advisers in the Oval Office earlier Friday, will speak at 4 p.m. from the Rose Garden, according to the White House. It will be the first time the president addresses the White House press corps in more than a week. Trump has been largely disengaged from the battle against COVID-19 at a moment when the disease is tearing across the United States at an alarming pace. Fresh off his reelection loss to President-elect Joe Biden, Trump remains angry that an announcement about progress in developing a vaccine came after Election Day. And aides say the president has shown little interest in the growing crisis even as new confirmed cases are skyrocketing and hospital intensive care units in parts of the country are nearing capacity. Public health experts worry that Trump’s refusal to take aggressive action on the pandemic or to coordinate with the Biden team during the final two months of his presidency will only worsen the effects of the virus and hinder the nation’s ability to swiftly distribute a vaccine next year.