China should stop exporting crude oil to North Korea after the reclusive nation defied the international community by testing a nuclear bomb on Sunday despite numerous international trade sanctions, experts told CNBC.
"If China decides to cut off that vital supply of crude oil going to North Korea, there will be an immediate and pretty costly impact on the economy," said Scott Seaman, director for Asia at geopolitical consultancy Eurasia Group.
The move, if implemented, would have a major impact on North Korea's military and transport operations, Seaman told CNBC's "Squawk Box."
North Korea has become "extremely adept" at moving around international sanctions, even though they may prove effective in the long run, said Jonathan Pollack, a senior fellow at Brookings Institution.
"The real issue here is whether China and Russia will be prepared to go into domains that until now they have not been prepared to enter and that very specifically concerns oil," Pollack told CNBC's "Street Signs."
"If the Chinese and the Russians both would be prepared to limit, or suspend outright, oil deliveries to the north, that's a very consequential step. It may have a much, much more potent effect than all of these issues related to sanctions," Pollack added.