"The thought of placing cyanide in the hands of the North Koreans, considering their record on human rights, political prisoners, and assassinations is not only risky but defies common sense", Haley said in a statement Friday.
The White House said it was aware that North Korea had launched a midrange ballistic missile.
Such tests present a hard challenge to new South Korean President Moon Jae-in, a liberal who took office on May 10 and has expressed a desire to reach out to North Korea.
Kim Heung-kwang, a former computer science professor in North Korea who defected to the South in 2004 and still has sources inside North Korea, said Pyongyang's cyber attacks aimed at raising cash are likely organized by Unit 180, a part of the Reconnaissance General Bureau (RGB), its main overseas intelligence agency.
Analysts said it represented a significant step forward in the North's weapons capabilities as it accelerates efforts to develop an intercontinental ballistic missile (ICBM) capable of delivering a nuclear warhead to the continental United States.
North Korea's latest launch came hours after Moon named his new foreign minister nominee and top advisers for security and foreign policy.
Pyongyang has long had missiles that can reach targets across the South and Japan.
While in the US, Hong also met with National Security Advisor H.R. McMaster to discuss the US's deployment of the Terminal High Altitude Area Defense system (THAAD) in South Korea and to review recent developments in the North's missile and nuclear program.
Turkey wants USA envoy removed in growing spat over Syrian Kurds
Turkey is frequently ranked as the world's top jailer of journalists, according to the Committee to Protect Journalists. Washington D.C. police, fire fighters, and EMS all responded, shutting down traffic in the area.
President Donald Trump is looking to both China and Russian Federation, the two permanent members on the Security Council that have historically been most sympathetic to North Korea, to join the USA -backed campaign of diplomatic and economic pressure on the North to get it to denuclearize.
With an imputed range of 4,500 kilometres, the Hwasong-12 also puts United States bases on the Pacific island of Guam within reach.
Kim singled out as "more serious" the push by the USA for a new sanctions resolution and the Trump administration's demand for all countries "to decide whether they support for DPRK or U.S". "This is serious. These threats are not welcome", Haley said ahead of the meeting.
"If you are a country that is supplying or supporting North Korea we will call you out on it", she warned.
Haley answered Putin and others who have made similar comments about the United States: "What about North Korea intimidating us?"
State newspaper Minju Joson Sunday threatened more launches.
"If the USA persists in confrontation with the DPRK (North Korea), the latter will show how the crime-woven history of the USA is put to an end", it said.
Leader Kim Jong-Un oversaw the launch and warned of "the worst-ever disaster" if the USA provoked the secrative state, claiming it is in "range of (nuclear) strikes", according to Rodong Sinmun on Monday.