China, on Tuesday, rejected President Barack Obama's suggestion that it was hiding from the risks posed by North Korea, and said it felt the dangers on the divided Korean peninsula more deeply than Washington.
Chinese Foreign Ministry spokesman Qin Gang made the rebuke in answer to repeated questions from reporters about comments by Obama over the weekend.
Beijing has refused to take a firm position on who is to blame for the sinking of a South Korean naval ship, the Cheonan, in late March, killing 46 sailors.
South Korea and other powers say the ship was undoubtedly sunk by a North Korean torpedo, and Pyongyang should suffer consequences. Beijing has urged restraint in dealing with the North, a long-time ally and strategic buffer.
"Now, I am sympathetic to the fact that North Korea is on China's border," Obama told a news conference at the end of the G20 global leaders' summit in Toronto.
"And so when they adopt a posture of restraint, I understand their thinking. But I think there's a difference between restraint and willful blindness to consistent problems," he added.
Chinese spokesman Qin suggested that his government had to be more cautious in handling its neighbour, whose struggling economy depends on Beijing for aid and trade. He said China did not want to "pour petrol on the flames."
"China is a neighbour of the Korean Peninsula, and on this issue our feelings differ from a country that lies 8,000 kilometres distant," Qin told a regular news conference, referring to the United States.
"We feel even more direct and serious concerns," he added.
The North's secretive leader, Kim Jong-il, appears to be in poor health, and his ruling communist party has called a rare meeting in September to elect a new leadership, a move analysts said could formally set in motion succession plans for him to set in place his son, Kim Jong-un, as his successor.
Beijing fears harsh condemnation of Pyongyang over the ship sinking could erode its already-limited leverage over Kim Jong-il, dash any hopes of persuading him to abandon his nuclear weapons, analysts say.
China's 1,415-km (880-mile) border with North Korea could also be overwhelmed by an influx of refugees if the North suffers political and economic collapse.
"On the Cheonan incident, we don't play favourites with any side," said the spokesman Qin. "Conflict on the (Korean) peninsula would suit no sides' interests, and so on this issue, China's position and efforts are beyond reproach."