What is the international regulation if one of the former president died during the sickness and Heatlh.?

Question

The president was from other country.

Answer 1

National mourning must be held in the country of the former President and there must be a ceremonial burial rite with a 21 gun salute.

Answer 2

As far as I'm aware, there are no international regulations regarding the deaths of foreign presidents, much less foreign ones.  Individual countries may have laws regarding what happens when a current or former leader of that countries dies, (a period of mourning, for example), but I don't believe there is an international regime in place for this.

Answer 3

There is no "international regulation." Each country has their own policy on that situation...including the USA.