Norks continue to call US bluff on nuclear weapons
An embargo would only work if China was an active participant. so far, it has not been willing to go that far. The one thing that has gotten China's attention is the anti-missile system the US is proposing for South Korea. Probably the best way to bring china on board is to not only push to beef that system up but also add it to the defense of Japan which has a few of them and Taiwan. That would get the Chinese attention and get them to do something about its Nork client. Their failure to do so could change the strategic balance in the region.
The United States must now decide whether to continue with sanctions, or pick among unpalatable alternatives such as imposing an embargo or resuming talks.