CHINA // China, North Korea's only major ally, hosts from Tuesday the chairman of the North's rubber stamp parliament, as part of a flurry of diplomatic efforts aimed at resolving the crisis on the Korean peninsula.
Choe Thae-Bok, the chairman of the North's Supreme People's Assembly and secretary of the Workers Party's Central Committee, is the most senior visitor from Pyongyang since the confrontation between the South and North flared last week.
After an initial muted response to North Korea's deadly artillery attack on a South Korean island, China called for emergency talks among the heads of the countries in the stalled six-party talks amid increasing global pressure to rein in reclusive Pyongyang.
Here are some facts about ties between the two countries.
COMRADES-IN-ARMS
Communist China was a key backer of North Korean Communist forces in the Korean War, and sent soldiers across the border into Korea from October 1950.
After the 1953 armistice, China kept supporting North Korea, helping with its rebuilding. In 1961, the two countries signed a treaty that calls for either to aid the other if attacked. It remains in force, but its potential application is ambiguous.
Following China's rapprochement with the West and then its establishment of formal diplomatic ties with South Korea in 1992, ties between Beijing and Pyongyang frayed.
In recent years, China has sought to shore up relations and increased aid to its poor neighbour, which it sees as a strategic buffer against the United States and its allies.
In early May, North Korea's leader Kim Jong-il visited China on his first trip abroad since 2006, and he visited again in late August, ahead of the anointment of his youngest son, Kim Jong-un, as heir-apparent in the dynastic one-party state.
But several media reports citing leaked US State Department cables have cast doubt on that close relationship. The cables say that some Chinese officials do not regard North Korea as a useful ally and would not intervene if the reclusive state collapsed.
NUCLEAR DIPLOMACY
China has pressed North Korea to abandon its nuclear weapons, and the issue has produced cracks in their relationship.
China has sought to defuse confrontation by hosting six-party nuclear disarmament talks since August 2003. The now-stalled negotiations bring together North and South Korea, China, the United States, Japan and Russia.
In October 2006, North Korea held its first nuclear test explosion, defying public pleas from China. Beijing condemned the test and supported a U.N. Security Council resolution that authorised sanctions against North Korea.
After the North's second nuclear test on May 25, 2009, Beijing backed a Security Council resolution authorising more sanctions on Pyongyang, including a ban on its arms exports.
In April 2009, North Korea said it was quitting the six-party talks and reversing nuclear "disablement" steps, unhappy with implementation of an initial disarmament deal reached in 2007.
North Korea has been retreating from its earlier public renunciation of the talks, but there are no plans for their resumption. South Korea and the U.S. say resuming the talks will be impossible until North Korea makes concessions over the recent sinking of one of Seoul's warships and shows it is serious about nuclear disarmament.
A U.S.-based think-tank, the Institute for Science and International Security (ISIS), has said North Korea used China as a transshipment point to obtain technology for a uranium enrichment facility that was shown to a visiting U.S. nuclear scientist. [ID:nLDE6AL11O]
China sent a senior diplomat, State Councillor Dai Bingguo, to meet South Korea's President Lee Myung-bak last weekend. Both countries expressed their anxieties about tensions in the Korean peninsula, the Chinese Foreign Ministry said.
Dai's visit follows Chinese Foreign Minister Yang Jiechi's meeting with North Korean ambassador Ji Jae Ryong in Beijing last week and telephone conversations with U.S. Secretary of State Hillary Clinton and South Korean Foreign Minister Kim Sung-hwan, during which Yang called for calm on the Korean peninsula.
Akitaka Saiki, Japan's chief envoy to the six-party talks, left for China on Tuesday to discuss North Korea-related matters with a senior Chinese diplomat, Wu Dawei, Japan's Foreign Ministry said.
SHIP SINKING
The sinking of a South Korean navy ship on March 26 deepened tensions between Pyongyang and Seoul and hurt Chinese ties with South Korea.
South Korea lost 46 sailors when its navy ship, the Cheonan, sank. Seoul said an inquiry found there was no doubt North Korea torpedoed the ship, but Pyongyang denied it was responsible.
China stayed low-key about the dispute, reflecting its desire to stay friendly with both North and South Korea. Beijing's approach irked Seoul, which wanted heavier pressure on Pyongyang.
In July, China backed a U.N. Security Council statement that condemned the sinking but stopped short of blaming North Korea.
Beijing was later angered by joint U.S.-South Korea naval exercises that those two countries said were aimed at warning North Korea. Beijing said those exercises could threaten its security and regional stability.
Last Friday, Beijing warned again against military acts near its coast as U.S. and South Korean forces prepared for exercises in the Yellow Sea to deter North Korea.
ECONOMIC FLOWS
China's trade and aid are crucial to North Korea's survival. In 2009, trade between China and North Korea was worth $2.7 billion, down 4 percent from 2008, according to Chinese customs statistics. In 2009, China's bilateral trade with South Korea was worth $156.2 billion.
REFUGEES
China's 1,415-km border with North Korea includes stretches of rivers that freeze over in winter, and in past years many North Korean refugees have crossed over, sometimes then making their way to other countries and then South Korea.
Outside groups have earlier estimated their numbers to be from tens of thousands to 300,000. Beijing worries that economic collapse or political turmoil in North Korea could unleash a surge of refugees into China.