The Tokyo Olympics, postponed in 2020 during the early days of the Covid-19 pandemic, are facing increasing hurdles in putting on a 2021 show, CNN.com reported. The latest troubling sign for the Summer Games came on Monday when the State Department advised U.S. citizens against traveling to Japan because of a sharp increase in Covid-19 cases. The "Level 4: Do Not Travel" advisory is the highest cautionary level in the department's hierarchy of warnings. It's been more than a year since Americans have paid tourist calls to the nation. Japan has been closed to U.S. leisure travelers throughout the pandemic, with only "very limited" circumstances in which US citizens could enter. The Games are still scheduled to run from July 23 to August 8 in Japan. Japan has seen a big increase in Covid-19 cases, which have steadily risen since a state of emergency was lifted in March. Its vaccine rollout has been slow compared with other places in Asia because of a shortage of medical professionals and a lack of syringes. Only about 2% of Japanese citizens have gotten at least one shot of the vaccine. Read more.