U.S. national security adviser John Bolton met with officials in Seoul on Wednesday amid Republic of Korea's (ROK) trade spat with Japan and stalled nuclear talks with Pyongyang.

Bolton met ROK's chief of National Security Office Chung Eui-yong, Defense Minister Jeong Kyeong-doo, and Foreign Minister Kang Kyung-wha to discuss issues including denuclearization of the Democratic People's Republic of Korea (DPRK) and ways to strengthen the ROK-U.S. alliance.

On his arrival in South Korea late on Tuesday, Bolton tweeted that he was "looking forward to productive meetings with the leadership of our important ally and partner so vital to Indo-Pacific security and prosperity". 

Seoul is expected to bring up a trade dispute with U.S. ally Japan, which has restricted exports of high-tech materials to the ROK. 

Seoul has said the curbs could hurt global tech companies including Apple which use its semiconductors and displays and has asked the United States to help resolve the dispute. 

Japan, which has denied that a dispute over compensation for South Koreans forced to work for Japanese occupiers during World War Two is behind the export curbs, is now considering removing the ROK from a Japanese "white list" of countries with minimum trade restrictions, which would impose tougher conditions.

On Tuesday, ROK officials said their warplanes had fired hundreds of warning shots near a Russian aircraft. Moscow said it carried out long-range joint air patrol in the Asia-Pacific region with China and denied that the bombers had violated ROK's air space. 

Denuclearization talks between the DPRK and the United States have stalled after a second summit between U.S. President Donald Trump and DPRK's leader Kim Jong Un in Vietnam in February broke down.

Kim and Trump met at the inter-Korean border on June 30 and agreed to resume their working-level nuclear talks within a few weeks.

The talks are expected to start in mid-July but Pyongyang reportedly did not respond to Washington's offer for dialogue. 

(Cover: U.S. national security adviser John Bolton shakes hands with Foreign Minister Kang Kyung-wha in Seoul, on July 24, 2019. /VCG Photo)