A senior USA official dismissed the South Korean diplomats' worries about a miscalculation and said a cautious approach by past US administrations had not stopped North Korea from developing nuclear weapons and ballistic missiles.
Chinese Foreign Minister Wang Yi and his Russian counterpart Sergei Lavrov urged all parties to seek a "peaceful resolution" to the current stand-off with Pyongyang over its nuclear weapons program, the Chinese foreign ministry said in a statement.
At a time when North Korea is making advances in its nuclear and missile programs, Niksch said that what Kim wants are military concessions from Moon, starting with a suspension of U.S.
Seoul is within artillery range of North Korea, which is also believed to have a sizable chemical and biological arsenal beyond nuclear and conventional weapons.
"The U.N. sanctions against [North Korea] explicitly recognize that special steps must be taken to ensure that sanctions don't add to the suffering of innocent children, too many of whom in [the country] are already experiencing malnutrition", said Chris de Bono, UNICEF's regional chief of communication in East Asia and Pacific.
The decision to send aid to North Korea was not popular in South Korea, hitting President Moon Jae-in's approval rating.
United States officials have expressed frustration in recent months over North Korea's continued nuclear aggression.
Another critic of the South Korean initiative, Larry Niksch, a Korea expert formerly with the U.S. Congressional Research Service, said $8 million is a token amount of aid, barely enough to have a significant impact on North Koreans in need.
If forced to defend itself and its allies, the USA "will have no choice but to totally destroy North Korea", Trump said, calling North Korean leader Kim Jong-un a "Rocket Man" on a suicide mission.
"Food and essential medicines and equipment to treat young children are in short supply", she said.
The new South Korean leader was scheduled to make his debut in the global arena Thursday when he delivers a keynote speech at a UN General Assembly session.
Moon will meet Japan's Prime Minister Shinzo Abe and Trump later on Thursday on the sidelines of the U.N. General Assembly, where North Korea was expected to be the core agenda item.
A United Nations report showed that about 72 percent of the 24.9 million North Koreans are suffering from food shortages and malnutrition.
So far, no North Korean athlete has qualified for PyeongChang, though there has been talk of the International Olympic Committee (IOC) granting wild cards, something previously proposed by Choi Moon-soon, governor of the Gangwon province that will host the Winter Games.
Regional tensions have risen since the reclusive North conducted its sixth, and by far its most powerful, nuclear test on September 3, along with a series of missile launches, including two that flew over Japan.