North Korea must 'earn its way back' to the negotiating table, US Secretary of State Rex Tillerson said, backing away from an earlier unconditional offer of talks to end the nuclear stand-off with Pyongyang.
Tillerson told the UN Security Council that a "sustained cessation of North Korea's threatening behaviour must occur before talks can begin," apparently after coming under pressure from President Donald Trump's White House to toughen his stance.
Earlier this week at a policy forum in Washington, Tillerson had underlined that the United States was seeking a diplomatic opening for negotiations with North Korea on ending its nuclear program and, for the first time, offered "talks with no preconditions."
According to a prepared version of his remarks to the Security Council, he had planned to say much the same thing again on Friday, but the line was apparently cut from his speech.
The White House had responded to Tillerson's remarks earlier in the week by insisting there has been no change in US policy, triggering a new round of reports of a rift between President Donald Trump and his chief diplomat.
At the United Nations, with North Korea's ambassador looking on, Tillerson took a tough line.
"North Korea must earn its way back to the table," he said. "The pressure campaign must and will continue until denuclearization is achieved."
"We will, in the meantime, keep our channels of communication open."
Tillerson repeated that "we do not seek, nor do we want, war with North Korea."
"The United States will use all necessary measures to defend itself against North Korean aggression, but our hope remains that diplomacy will produce a resolution," he said.
'China is helping. Russia is not helping'
North Korea's UN ambassador Ja Song-Nam made a rare appearance at the council meeting chaired by Japan, which announced new targeted sanctions on Chinese entities, among others.
Singling out China, Pyongyang's sole ally, and Russia, Tillerson urged Beijing and Moscow to take unilateral steps that go beyond the current tough UN sanctions resolutions.
"Continuing to allow North Korean laborers to toil in slave-like conditions inside Russia in exchange for wages used to fund nuclear weapons programs calls into question Russia's dedication as a partner for peace," he said.
The United States has called on China to cut off oil supplies to North Korea, a move that would deal a crippling blow to its economy.
In Washington, US President Donald Trump criticized Russia for not doing enough to pressure North Korea to change course.
"China is helping. Russia is not helping. We would like to have Russia's help," said Trump, who discussed North Korea by phone with President Vladimir Putin on Thursday.
Pyongyang has carried out its sixth nuclear test and conducted a series of missile launches including its first tests of two intercontinental ballistic missiles (ICBM) this year.
In his address to the Security Council, UN Secretary-General Antonio Guterres urged diplomatic engagement with North Korea and said the United Nations could play a role to promote contacts.
"We must do everything we can to reach that objective - and avoid a level of danger that would be unpredictable in its trajectory and catastrophic in its consequences," said Guterres.
The UN's political affairs chief, Jeffrey Feltman, returned at the weekend from talks in Pyongyang - the first visit to the North by a high-ranking UN official since 2011.
While Feltman received no firm commitment from North Korea to open talks, he has said the visit is "just the beginning" of his push for "talks about talks."
Since late 2016, the council has slapped three rounds of sanctions aimed at choking off revenue to Pyongyang's weapons program, which the United Nations has described as the most dangerous security issue in the world today.
China and Russia argue that sanctions alone will not compel North Korean leader Kim Jong-Un to change course and want to step up diplomatic efforts to achieve a solution.
Tillerson appeared to dismiss concerns that UN sanctions are having an impact on North Korea's humanitarian crisis, saying Pyongyang "hypocritically spends billions" on its military programs "while its own people suffer great poverty."
In Tokyo, the government said it had added 19 more entities to its sanctions blacklists including seven from China, one from Singapore and two from Namibia.
"The international community must continue to coordinate and apply pressure until North Korea changes its policies and seeks negotiations," Prime Minister Shinzo Abe said.