Trump to press China on North Korea, trade on Beijing visit

* Trump to step up pressure on China over N.Korea, official says

* U.S. says China needs to do more to comply with UN resolutions

* China says U.S., S.Korea also share responsibility

* U.S., S.Korea and Japan start missile tracking drill

* Trump's longest overseas trip to include Japan, South Korea (Adds trilateral drills, paragraphs 9-10; adds bullet points)

By Steve Holland and Matt Spetalnick

WASHINGTON, Oct 23 (Reuters) - U.S. President Donald Trump will urge President Xi Jinping to make good on his commitments to pressure North Korea when he visits China next month, a senior White House official said on Monday, stepping up a strategy to have Beijing help rein in Pyongyang.

Isolating North Korea further over its nuclear and ballistic missile tests is a key goal for Trump on what will be his longest foreign trip to date.

Trump will call on Xi to fully implement U.N. Security Council resolutions against Pyongyang and take other steps to pressure North Korea.

China, North Korea’s sole major ally, accounts for more than 90 percent of trade with the isolated country.

China has said it will strictly enforce U.N. Security Council sanctions banning imports of coal, textiles and seafood, while cutting off oil shipments to the North.

But a senior White House official who briefed reporters ahead of Trump's trip said China needs to do more to comply with two U.N. Security Council resolutions that were approved unanimously, including with China's support.

"We would like to see China follow through on those commitments. We would like to see China do things bilaterally as well that might even go beyond things that are mandated by those U.N. Security Council resolutions," the official said.

Though China has been angered by North Korea’s repeated nuclear and missile tests and demanded they stop, Beijing also sees the United States and South Korea sharing responsibility for rising tensions because of military drills they carry out in the region.

South Korea, the United States and Japan started a two-day missile tracking drill on Tuesday, South Korea's military said in a statement, in preparation for any missile or nuclear threats from North Korea.

The exercises will be held in waters off the coasts of South Korea and Japan, South Korea's Joint Chiefs of Staff said, with four Aegis combat system-equipped ships from all three countries participating in the drill.

"CRITICAL" THREAT

China's special envoy for the North Korea nuclear issue, Kong Xuanyou, met his U.S. counterpart, Joseph Yun, in Beijing on Monday, China's Foreign Ministry said, where they had a "deep exchange of views on the Korean peninsula issue". The ministry did not elaborate.