【明報專訊】THE POLITICAL SITUATION of Northeast Asia is unpredictable. The supreme leader of North Korea Kim Jong-un visited China for the second time in 6 weeks. This is absolutely unusual. Recently North Korea's Ministry of Foreign Affairs has suddenly criticised the United States openly. It seems that the US-North Korea summit is faced with obstacles. The fact that Kim met Xi Jinping again shows that North Korea is anxious to seek Chinese support and some people's claim that "China has been marginalised" is obviously untenable. The obstacles faced by the US-North Korea summit stemmed from Washington's insistence that the US would only ease sanctions after North Korea "completely relinquish its nuclear programme". Xi Jinping urged the US to "consider North Korea's reasonable security concerns" and "act in stages". China is throwing its weight behind North Korea and is urging Washington to make concessions to prevent the US-North Korea summit from falling through.