The U.S. is still considering a military response if North Korea conducts another nuclear test.
In a press briefing last Thursday, U.S. State Department spokeswoman Victoria Nuland answered a question about a possible pre-emptive strike on the North by saying, "Well, obviously we don't take anything off the table. We never do."
One military response could be a massive show of force like a joint South Korea-U.S. military exercise, pundits speculate.
The U.S. is also reportedly considering a maritime blockade. An expert with a government-funded think tank said, "A wholesale maritime blockade could lead to an armed conflict, so it's more likely to be partial and symbolic, taking the form of intensified searches and interdictions of North Korean ships suspected of carrying contraband such as weapons."