The South Korean military says even without a bilateral pact, classified information can still be shared between Seoul and Tokyo through Washington.
On Friday, Seoul's defense ministry told reporters that it will continue and strengthen the sharing of military information between the three through TISA, or the Trilateral Information Sharing Arrangement.
TISA was signed back in 2014 a year after the North carried out its third nuclear test.
The three countries felt the need to exchange intelligence in light of the North's growing nuclear and missile threats.
TISA enables Seoul and Tokyo to share information with each other via the U.S.
South Korea and Japan send the U.S. information, which the U.S. then evaluates and sends to the other side.
The information can take oral, visual, or written form.
Concerns are that it could take longer for South Korea and Japan to exchange intel and it could reduce the quality of the information compared to GSOMIA.
But the level of information shared through TISA differs case by case -- it could be level two or three, but sometimes level one.
And Seoul says the three countries will be working to share worthwhile information upon sufficient consideration.
"GSOMIA will remain in effect for 90 more days. Until November 22nd, South Korea's military says it will be sharing information directly with Japan as necessary. Oh Jung-hee, Arirang News."