Most of the officials were based in China and Russian Federation for companies the Treasury said acquire materials, technology and financial support for North Korea's defense industry.
The comments come ahead of Trump's planned summit with Chinese President Xi Jinping at the president's Mar-a-Lago resort in Palm Beach, Florida.
"All the parties and people from all walks of life in South Korea should rise up in the anti-U.S., anti-war struggle for peace, clearly seeing through the nature of the U.S., the chieftain of aggression and disturber of peace", the letter said in part. "And China will either decide to help us with North Korea, or they won't".
The official, from the North Korean Sports Ministry, reportedly told Choi that the North Koreans will attempt to send "as many athletes as possible" through qualifying events.
While China provides diplomatic and economic support to its neighbor, it claims that its influence over Kim Jong Un's government is limited.
North Korea tests new engine for nuclear missile
Tourism, transport business and cultural exchanges between China and South Korea have all reportedly suffered since the spat. Tillerson's visit to Beijing is the final stop on his three-nation swing through Northeast Asia, which began in Japan.
Also speaking on ABC, he recalled that the United States drew up a "preemptive strike plan" in 1994 to knock out North Korea's Yongbyon reactor, during a confrontation over its nuclear program. During his campaign he accused China of unfair trade practices and threatened to raise import taxes on Chinese goods and declare Beijing a currency manipulator, though it is unclear whether Trump will follow through with either threat.
Such encounters are a break from tensions that have dominated bilateral ties since the 1950-53 Korean War, with Seoul recently warning of a looming sixth North Korean nuclear test.
She said the condemnation will stand because "we can't change what they did, but we can sure change our actions in how we deal with it".
"We have been giving our best efforts to beat North Korea", he said.
In a wide-ranging interview with four news agencies, Haley also talked about the new USA priorities in Syria and American efforts "to create balance" at the United Nations on the Israeli-Palestinian conflict. When pressed about whether he could do it one-on-one without China's help, the president said, "I don't have to say any more". "Proving it really is showing them through pressure that you are going to cut them off, and that you take this as seriously as the rest of the world does", she said.