U.S. Ambassador Nikki Haley called a new United Nations resolution against North Korea over its banned missile program "the most stringent set of sanctions on any country in a generation."
But she said on August 5 that the measures were not enough and that "we should not fool ourselves into thinking we have solved the problem — not even close."
"The threat of an outlaw nuclearized North Korean dictatorship remains...[and] is rapidly growing more dangerous," Haley told the UN Security Council after the vote.
U.S. President Donald Trump hailed the sanctions, writing on Twitter that "The United Nations Security Council just voted 15-0 to sanction North Korea. China and Russia voted with us. Very big financial impact!"
A White House statement later said, "The president appreciates China's and Russia's cooperation in securing passage of this resolution."
The Security Council voted unanimously to impose its toughest sanctions ever against North Korea after Pyongyang tested two intercontinental ballistic missiles (ICBM) in July, claiming it now had the ability to launch a strike against the entire United States.
U.S. Secretary of State Rex Tillerson, who is meeting with South Korean Foreign Minister Kang Kyung-wha in the Philippines on the sidelines of a regional summit, said the approval of the new UN sanctions was a "very good outcome."
Tillerson said he and the South Korean foreign minister plan to discuss the sanctions during their meeting, along with next steps to pressure Pyongyang, on the sidelines of the Association of Southeast Asian Nations (Asean) in Manila.
Kang said the new sanctions were a "very, very good outcome."
Meanwhile, Chinese Foreign Minister Wang Yion urged his North Korean counterpart to abide by UN resolutions and stop provoking "the international community's goodwill" with missile launches and nuclear tests.
Wang spoke to reporters in Manila after meeting with North Korean Foreign Minister Ri Yong Ho on the sidelines of the summit.
Wang said the two had an intensive conversation during which China urged North Korea to maintain calm. Wang said he told Ri "do not violate the UN decision or provoke the international community's goodwill by conducting missile launches or nuclear tests."
Wang also urged the United States and South Korea "to stop increasing tensions" and said that all sides should return to negotiations.
In an earlier statement on August 6, Wang appealed to other governments to resume six-nation talks that involve North Korea, the United States, Russia, Japan and South Korea, as well as Beijing.
Tillerson was due to meet Wang and Russia's Foreign Minister Sergei Lavrov later on August 6, seeking to intensify North Korea's diplomatic isolation and reduce the risk of renewed conflict.
The key element of the U.S.-drafted sanctions is a ban on North Korean exports of coal, iron, lead, and seafood products, and a ban on all countries importing the products.
The exports are estimated to bring in more than $1 billion a year in hard currency for Pyongyang, about one-third of the country’s $3 billion in annual exports.
The resolution also prohibits countries from increasing the current numbers of North Korean workers abroad and bans new joint ventures with North Korea and any new investment in current joint ventures.
The resolution adds nine individuals and four entities to the UN blacklist, including North Korea's primary foreign exchange bank, subjecting them to a global asset freeze and travel ban.
All 15 members of the Security Council said the aim was to increase economic pressure on Pyongyang to bring it back to the negotiating table over its nuclear and missile programs.
Prior to the new resolution, the Security Council had imposed six rounds of sanctions, but they have failed to halt North Korea’s drive to develop its ICBM and nuclear weapons capabilities.
Pyongyang has said its weapons program is necessary to oppose U.S. aggression.
Russia and China approved the resolution and did not invoke their veto rights. However, both expressed words of caution.
Russia's ambassador to the UN, Vasily Nebenzya, warned that "sanctions cannot be a goal in itself" but should be seen as a tool to help engage North Korea in negotiations.
He added it was Russia's position that the new sanctions should not be used for the "economic strangulation" of North Korea which, he said, would lead to a deterioration of the humanitarian situation.
China and Russia both criticized the U.S. deployment of the THAAD antimissile defense system in South Korea, with China’s ambassador, Liu Jieyi, calling for a halt to the deployment.
Liu also urged North Korea to "cease taking actions that might further escalate tensions."
With reporting by Reuters, the BBC, dpa, and TASS