Some countries evidently are lying to save face, others are simply overwhelmed:
Covid-19 deaths in India, Mexico, and Russia — countries with the second, third, and fifth highest tolls (the U.S. has the number one spot) — were also vasty undercounted. ... Researchers additionally found that the tolls in Japan, Egypt, and several other countries are 10 times higher than the reported numbers.
Mediaite has the story here.