Mods/admins feel free to move this thread if this is not the appropriate section for this. Anyways, Japan post has an official announcement regarding suspension of international mail: https://www.post.japanpost.jp/int/information/2020/0401_02_en.html
Please check the PDF for the specific list of countries and what type of mail is affected. If I understand the PDF correctly, US (and Canada) for example can still accept EMS/Airmails. SAL on the other hand (not sure if it also includes RSAL sm
Good news, looks like EMS will be resuming for US / North America this June or summer. The bad news, it's more expensive with the introduction of a "temporary" surcharge. Less than 1.5kg, the rate is somewhat acceptable but more than that, courier shipping will look like a better option. For example, for 2kg EMS will cost 6100 yen. For 5 kg, 12700 yen. Also the surcharge is not flat, the higher the base rate (or weight), the higher the surcharge. Link to the table (in Japanese): https://www.post