File Photo: U.S. Secretary of State Mike Pompeo shakes hands with Japan's Foreign Minister Taro Kono before a breakfast meeting in Tokyo, Japan, July 8, 2018. (Xinhua/Reuters)

WASHINGTON, Sept. 21 (Xinhua) -- U.S. State Department said here on Friday that Secretary of State Mike Pompeo had spoken by phone with Japanese Foreign Minister Taro Kono on Thursday to discuss the denuclearization of the Democratic People's Republic of Korea (DPRK).

According to a statement issued by State Department spokesperson Heather Nauert, Pompeo and Kono discussed "the ongoing pressure campaign to achieve the final, fully verified denuclearization of the DPRK as agreed to by Chairman Kim Jong Un in Singapore."

"They also talked about the upcoming UN General Assembly and global security issues of importance to the U.S.-Japan alliance," read the statement.

The White House on Thursday announced that U.S. President Donald Trump will during the UN General Assembly next week meet with Japanese Prime Minister Shinzo Abe, among all leaders.

During his Sept. 18-20 trip to Pyongyang, South Korean President Moon Jae-in held talks with the top leader of the DPRK, Kim Jong Un, and signed the Pyongyang Declaration on further steps towards the Korean Peninsula's denuclearization and concrete measures to end hostile acts near inter-Korean border areas.

However, the U.S. State Department on Thursday said the denuclearization of Pyongyang has to come first before the U.S. side gives any corresponding reciprocal measures.