UPDATE - North Korea confirms leader's China trip

ADDS REACTIONS BY JAPAN, S. KOREA

By Alex Jensen

SEOUL (AA) - North Korea announced Wednesday that its leader Kim Jong-un made an "unofficial" visit to China this week, following earlier claims that he had travelled abroad for the first time since taking power in 2011.

Media speculation intensified after a special North Korean train arrived in China amid heavy security on Sunday.

The North's state-run radio station confirmed Kim was invited by Chinese President Xi Jinping, who reportedly accepted a request to visit the North at his convenience.

Kim was joined by his wife and senior officials, just weeks before planned summits with his counterparts in South Korea and the United States, Moon Jae-in and Donald Trump.

Moon and Trump are aiming to bring about North Korea's denuclearization following years of tensions in the region.

In that regard, Kim's message was positive and in line with talks he held with visiting South Korean officials earlier this month.

"It is our consistent stance to be committed to denuclearization on the peninsula," he was quoted as saying by China's Xinhua News Agency.

But Kim also insisted South Korea and the U.S. must "respond to our efforts with goodwill, create an atmosphere of peace and stability while taking progressive and synchronous measures for the realization of peace".

Meanwhile, the South's presidential office was notified by China in advance of Kim's trip, according to an official cited by local news agency Yonhap.

Both Seoul and Washington had been cagey in response to this week's media speculation, refusing to verify the story.

A White House statement released after Wednesday's confirmation revealed that China had also briefed the U.S. on Kim's visit, celebrating the communication as "further evidence that our campaign of maximum pressure is creating the appropriate atmosphere for dialogue with North Korea".

Japanese Premier Shinzo Abe told parliament that he "wants to receive a thorough explanation from China" on Kim's visit.

Abe said, "At this point, we are in a situation where North Korea is in the process of negotiation. What is important is that North Korea gives up its nuclear and missile programs completely and irreversibly."

Japan’s Chief Cabinet Secretary Yoshihide Suga said sanctions against North Korea should continue until concrete steps are taken.

South Korea’s Foreign Ministry "welcomed" the talks in a written statement.

"The government welcomes Chairman of the State Affairs Commission Kim Jong-un's trip to China from Sunday to Wednesday and his talks with Chinese leaders," the statement said.

It also said, "The government hopes that the latest China visit by Chairman Kim, which came ahead of inter-Korean and North-United States summits, will contribute to denuclearizing and building peace on the Korean Peninsula."