Referring to North Korea, he remained downbeat about the current United States and South Korean leaders' ability to resolve what he described as a "really tough sort of problem".
As Chinese President Xi Jinping prepared to inaugurate the Belt and Road Forum, Pyongyang fired a ballistic missile from a base in the country's northwest, near the border with China.
Multiple sets of United Nations and USA sanctions against North Korea have done little to deter it from pursuing its nuclear and missile ambitions.
He says officials are studying possible implications of the launch that came days after South Korea's new president took office and an worldwide conference is being hosted by China.
The U.N. envoy told ABC's "This Week", that the missile test appeared to be meant to send a message to South Korea and said North Korea's missile program was "getting kind of close to home" for Russian Federation.
Japan's Chief Cabinet Secretary Yoshihide Suga says the missile test-fired by North Korea flew 800 kilometers (500 miles) for about 30 minutes and landed in the Sea of Japan, but not inside Japan's exclusive economic zone.
Trump to launch panel to investigate voter fraud
Voting machines in many jurisdictions around the nation are outdated, and lines at polling places can stretch discouragingly long. He said he was sending his application for the commission Thursday and hoped to be selected, albeit as a skeptical voice.
It impacted "so close to Russian soil ... the president can not imagine that Russia is pleased", the White House said.
Unsettled by North Korean missile and military nuclear programs, the United States has adopted a war-like posture, sending a strike group to the region and conducting joint military drills with North Korea's regional adversaries, Japan and South Korea.
Newly-elected South Korean President Moon Jae-in also condemned the launch as a "reckless provocation".
Pyongyang defends its missile and nuclear programs as means of protecting the country from USA hostility.
Tensions have been soaring high on the Korean Peninsula over the past weeks.
Before the missile test, the US Treasury said it was considering "every tool in our arsenal" to cut off sources of global financing for illegal activities in the North. Past North Korean missiles have flown farther than Sunday's test, landing closer to Japan, but this launch follows a series of high-profile failures. "And, in the short term, North Korea's missile capability is still some distance from Washington's red line - where it presents a real threat to United States territory".
Trump tax plan stands to benefit the man in the White House
Sanders said Trump's tax plan saying that it not only perpetuates a rigged system, but that it exacerbates it even further. And if he's really worth the $10 billion he claims? And his heirs could eventually enjoy his enormous assets tax-free.
China, North Korea's most important ally and key provider of food and fuel aid, has sought to cool tensions over Pyongyang's nuclear and missile programs, repeatedly calling for dialogue.
"This missile launch represented no danger for the Russian Federation", the ministry said in a statement on Sunday carried by official Russian news agencies. And the White House says the latest "provocation" should serve as a call for all nations to implement far stronger sanctions against the North.
"Basically, Pyongyang wanted to grab as many chips as possible before sitting down at the negotiating table", Cai said. On Saturday, a top North Korean diplomat said Pyongyang was open to dialogue with the Trump administration under the right conditions.
It said President Donald Trump's "maximum pressure and engagement" policy is only aimed at "stifling us" and will compel the North to "strengthen our nuclear deterrent at the maximum speed".
North Korean attempted but failed to test-launch ballistic missiles four times in the past two months.
North Korea has conducted seven previous launches since the beginning of the year, though the most recent - on April 29 - was a failure, according to South Korean and US officials. It also conducted its fourth and fifth nuclear tests a year ago.
Clippers announce Blake Griffin to miss rest of playoffs with toe injury
Forward Blake Griffin left Friday's Game 3 win over the Utah Jazz with what was described as a bruised right toe, not to return. The team announced Saturday that the five-time All-Star was diagnosed with an injury to the plantar plate of his right big toe.