Armed with extraordinary new U.N. sanctions, nations raced Monday to ensure that North Korea's biggest trading partners actually carry them out, an elusive task that has undercut past attempts to strong-arm Pyongyang into abandoning its nuclear weapons.
The United States and South Korea remain technically still at war with North Korea after the 1950-53 Korean conflict ended with a truce, not a peace treaty.
Mr Tillerson's remarks might be an attempt to try another tack by the United States, which has also tried to get Pyongyang's ally China to use its influence to prevent North Korean leader Kim Jong-un from building a nuclear arsenal. Then all parties should come to the negotiating table.
Pyongyang's United Nations mission contended that new U.N. sanctions against it for its missile tests were a "flagrant infringement upon its sovereignty", with state media claiming they were the result of a "heinous USA plot to isolate and stifle" the communist country.
"We'll know it when we see it", Tillerson said.
"This is not a "give me 30 days and we are ready to talk" - it's not quite that simple", Tillerson added. "So it is all about how we see their attitude towards approaching a dialogue with us". The regime threatened "strategic" and "physical" actions against the US, which spearheaded the sanctions.
Meanwhile, Pyongyang lambasted tough new sanctions adopted over the weekend by the U.N. Security Council as an act of terror.
Such concerns were on display Sunday in a dizzying display of fast-paced diplomacy spanning multiple continents.
North Korea's main objectives for attending the Association of Southeast Asian Nations (ASEAN) gathering in Philippine was to stop its missile from launching but not to sign the proposal sanction by the U.N. The foreign minister clearly pointed out the threat from Japan and its allies are one of the reasons why not surrendering its arsenal is the right thing to do for the security of its nation. The American and Japanese diplomats held another three-way session with Australia.
The DIA 's latest assessment comes against a backdrop of growing global concern regarding North Korea's nuclear and missile testing.
Harry Kazianis, director of defense studies at the Center for the National Interest, said the new sanctions "will succeed or fail based on what China does", and he predicts what China does will be more of the same: "talk tough on North Korea and yet provide direct and indirect aid to keep (its) economy moving". Moon's office said that he and Trump had agreed to apply "the maximum pressure and sanction". The UN estimates the move will cost North Korea $1 billion per year.
The resolution includes a complete ban on the North's exports of coal, a major source of money needed to advance its weapons program. Chinese Foreign Minister Wang Yi, meeting with North Korea's top diplomat during the gathering in Manila, urged the North to "maintain calm" despite the United Nations vote.
Even if implemented well, trade accounts for a modest percentage of North Korea's overall gross domestic product and the country has grown adept at economising its pursuit of a nuclear deterrent.
The diplomatic wrangling sought to build on the sweeping new North Korea sanctions passed by the U.N. Security Council a day earlier the strongest in a generation, the USA said. Last month's pair of groundbreaking tests of long-range ballistic missiles has put the continental United States in range for the first time.
"The ministers expressed their grave concern over recent developments in the Korean Peninsula including the most recent testing by the Democratic People's Republic of Korea [DPRK] of intercontinental ballistic missiles [ICBMs] on July 4 and July 28, 2017 and previous ballistic missile launches and two nuclear tests in 2016", the statement said.