Classified Japanese diplomatic information was leaked following Chinese cyberattacks on the Foreign Ministry in 2020, a government source said Monday, exposing the nation's digital vulnerability, Paralel.Az reports citing Kyodo.

Japan detected the large-scale attack and release of diplomatic telegrams during a period of government under then Prime Minister Shinzo Abe, the source said, but the nature of the leaked information is still publically unknown.

Tokyo and Washington discussed countermeasures in the wake of the leak of the diplomatic telegrams, which are highly confidential documents exchanged daily between the ministry and diplomatic missions abroad, the source said.

The diplomatic telegrams were sent via an encrypted Internet Protocol Virtual Private Network, or IP-VPN, according to the source. The use of this kind of network is critical in the transfer of sensitive data.

Japanese Chief Cabinet Secretary Yoshimasa Hayashi said at a press conference that the government of Prime Minister Fumio Kishida has not confirmed that secret Foreign Ministry information was accessed through the cyberattacks.