Friendship or leverage: Why is Xi Jinping in North Korea?

For Chinese leader Xi Jinping, North Korea is the neighbour China can neither control nor afford to lose.

The two sides often describe their relationship as one "forged in blood", a reference to the Korean War.

Yet in recent years, mistrust has strained ties. And now Beijing is trying to reassert sway over a strategically vital yet deeply unpredictable partner.

China wants stability on its border and influence in Pyongyang, but without being dragged into crises triggered by North Korea's nuclear ambitions.

So Xi's visit this week - he arrived in Pyongyang on Monday - is likely to be less about friendship, more about leverage.

Seoul believes he may try to position China as a mediator between North Korea and the United States, but Beijing may have other motives.

Western diplomatic sources tell the BBC that China has become increasingly concerned about the growing partnership between Pyongyang and Moscow.

After meeting Russian leader Vladimir Putin last week, Xi may want to ensure he also keeps North Korean leader Kim Jong Un in check, especially as Beijing increases its presence on the global stage.

The cooling between Beijing and Pyongyang was visible, even if subtle.

They barely marked the 75th anniversary of diplomatic relations in October 2024. Public messaging was muted.

China's ambassador did not attend North Korea's founding celebrations the previous month. There were no senior level exchanges throughout the year, a stark contrast with Pyongyang's increasingly warm relationship with Moscow.

After Russia's invasion of Ukraine, North Korea has expanded military cooperation with Putin, culminating in a mutual defence pact that was signed during Putin's visit to Pyongyang in 2024.

About 2,300 North Korean soldiers have died fighting for Russia against Ukraine, according to a BBC investigation. Pyongyang is also accused of supplying ammunition for Russia's war effort in exchange for oil and aid, a development that has alarmed Washington and its allies, and quietly rattled China.

"China wants to ensure that its interests vis-a-vis North Korea are protected at a time of rapid convergence between Moscow and Pyongyang," adds Ankit Panda, a nuclear policy specialist at the Carnegie Endowment for International Peace.

China has only one formal defence treaty, and that is with North Korea.

So Beijing is unlikely to welcome a scenario where Russia becomes the dominant influence in Pyongyang. A more confident, less dependent Kim would mean reduced Chinese leverage.

Beijing has responded by trying to reset the relationship. Late last year, Xi invite