China will go a long way toward determining whether the new sanctions really do have bite, analysts say.

"As long as China allows North Korea to operate, as long as China provides food, energy assistance and investment, the sanctions really don't matter," said Doug Bandow of the Cato Institute.

North Korea notoriously allows many of its people to live in malnutrition and starvation. Still, the country needs a functioning economy, partly to finance its military, Bandow said.

U.S. State Department spokeswoman Victoria Nuland said the United States is committed to taking action to compel North Korea to alter its approach.

"We're ... going to continue to increase the pressure if they don't make the right choice," Nuland said.