U.S. Secretary of State Rex Tillerson said Sunday that diplomatic efforts aimed at resolving the North Korean crisis "will continue until the first bomb drops". The U.S. must be prepared to defend itself and its allies, he said.
"There is no need for us to be bellicose and aggressive (over North Korea)", Clinton told the World Knowledge Forum in the South Korean capital of Seoul on Wednesday.
It comes as Kim Jong-un said he would never negotiate with Donald Trump's Government.
Following North Korea's most powerful nuclear test, the U.N. Security Council capped North Korean imports of crude oil, but China and Russian Federation resisted an outright ban.
Mrs. Clinton also indirectly referred to Mr. Trump's social media comments on North Korea, saying, "the insults on Twitter have benefited North Korea, I don't think they've benefited the United States".
In turn, the North called Trump "mentally deranged" and a "mad dog".
The United States and South Korea on Monday began a 10-day joint naval exercise in a fresh show of force against the North, with a USA aircraft carrier and two U.S. destroyers taking part.
North Korea's deputy United Nations ambassador warned on Monday that the situation on the peninsula "has reached the touch-and-go point and a nuclear war may break out any moment".
"The Chinese can't have it both ways", Clinton said.
The sanctions add three more top North Korean officials and six businesses to a blacklist banning them from travel to the European Union and freezing their assets. "They can't do less than they could to tighten economic pressures on North Korea and same time discount the real threat South Korea and its citizens face".
The party central committee said in the message carried by the official KCNA news agency: "We are greatly pleased over this".