The following is a chronology of recent events concerning North Korea and China.

Aug. 14, 2017 -- China formally issues an order to implement U.N. sanctions on North Korea, including a ban on all imports of coal, iron, iron ore, lead and seafood.

Sept. 3 -- North Korea conducts its sixth nuclear test.

(KNS/Kyodo)

Sept. 23 -- China imposes limits on petroleum product exports to North Korea and banned imports of textiles from the country in line with the latest U.N. sanctions.

Oct. 25 -- North Korean leader Kim Jong Un sends a congratulatory message to Chinese President Xi Jinping on his being re-elected to lead the Communist Party of China.

(Buildings on the North Korean side of the border as seen from Tumen, China)

Nov. 1 -- Xi sends a return message to Kim.

Nov. 17 -- Song Tao, head of the Chinese Communist Party's International Department, visits North Korea as Xi's special envoy.

(Song Tao, 3rd from right; Workers' Party of Korea vice chairman Ri Su Yong, left)

Nov. 29 -- North Korea claims it successfully test-fired a new intercontinental ballistic missile that is capable of hitting anywhere in the United States with a nuclear warhead.

(Photo courtesy of Korea Media)

Jan. 1, 2018 -- Kim, in New Year's address, expresses readiness to send athletes to Winter Olympics in Pyeongchang in South Korea.

Feb. 10 -- South Korean President Moon Jae In and Kim Yo Jong, sister and close aide to Kim Jong Un, hold talks in Seoul. The North invites Moon to visit North Korea.

Feb. 25 -- A high-level North Korean delegation visits South Korea for the closing ceremony of Olympics and meets with Moon.

March 5 -- South Korea's special envoys visit North Korea and hold talks with Kim.

(Photo courtesy of the South Korean presidential office)

March 6 -- South Korea's presidential office unveils the outcome of the envoy's meeting with Kim, including agreement to hold a summit meeting between the two Koreas in late April.

March 8 -- A senior South Korean official says U.S. President Donald Trump said he would meet Kim by May to achieve permanent denuclearization.

March 12 -- A senior South Korean official visits Beijing to hold talks with Xi.

March 17 -- Kim sends a congratulatory message to Xi on his being re-elected China's president.

March 25 -- Kim visits China, marking his first trip to another country as North Korea's supreme leader.

March 26 -- Kim holds summit with Xi in Beijing.


Related coverage:

N. Korea's Kim makes surprise visit to Beijing, meets China's Xi

In Pictures: Key events related to North and South Korea, and the U.S.

Japan tells North Korea it wants leader's talks

Trump to meet Kim Jong Un by May for 1st U.S.-N Korea summit

2 Koreas to hold summit in April, North eyes nuclear talks with U.S.