Japanese police will be on the highest level of alert for the Group of Seven summit in Hiroshima that kicks off Friday.
The National Police Agency said it will deploy up to 24,000 personnel, the biggest number for any summit in Japan since 2000.
The top policing body committed 21,000 personnel to the 2008 Hokkaido Toyako Summit, and 23,000 to the 2016 Ise-Shima Summit.
The NPA Commissioner General will oversee a Special Security Office from Thursday to Monday, when G7 leaders are expected to be in the country.
Police will also dispatch specialized squads, including the explosive ordnance disposal squad, the anti-firearms squad and the counter-NBC terrorism squad, which deals with the threat of biological and chemical weapons.
A squad equipped with anti-drone jamming guns will also be on standby.
Police have beefed up their security measures following an incident in April where an attacker threw an explosive at Prime Minister Kishida Fumio during an election campaign event in Wakayama Prefecture, western Japan. Kishida was not injured.
Police are also stepping up patrols around venues where G7 leaders will gather and other sites they are scheduled to visit. They will conduct advance sweeps for unusual items and question suspicious-looking people.