The Association of Southeast Asian Nations (ASEAN) gathering came a day after the United Nations imposed tough new sanctions on Pyongyang for its nuclear and missile programs and less than a week after Tillerson vowed that the USA has no intention of overthrowing the dictatorship of Kim Jong Un.
Just hours before the meetings were due to start, the UN Security Council voted unanimously to back a US-drafted resolution to dramatically tighten the existing sanctions targeting North Korea. The resolution would ban North Korean exports of seafood, coal, lead, lead ore, iron and iron ore.
China reiterated its support for the UN Security Council's sanctions on North Korea, saying it would adhere to them very strictly.
Ri also stressed that that North Korea was a "responsible nuclear power and ICBM (intercontinental ballistic missile) state", adding that it has "no intention to use nuclear weapons against or threaten with nuclear weapons any other country except the U.S., unless it joins military action of the USA against North Korea" - possibly referring to China and Russian Federation, who have in the past provided diplomatic cover for Pyongyang. "Very big financial impact!"
The North said it would take an unspecified "resolute action of justice" and would never place its nuclear program on the negotiating table or "flinch an inch" from its push to strengthen its nuclear deterrence as long as US hostility against North Korea persists.
The UN Security Council on Saturday imposed its toughest round of sanctions yet against Pyongyang over its two intercontinental ballistic missile tests in July. "We must be tough and decisive!"
Thornton says the USA wants to ensure that with the new sanctions, there's "not this kind of episodic back and forth that we've seen". "Neither shall we flinch even an inch from the road to bolstering up the nuclear forces chosen by ourselves unless the hostile policy and nuclear threat of the United States against North Korea is fundamentally eliminated".
Trump, whose administration is moving to crack down on leaks of USA government information, also retweeted a Fox News report based on anonymous sources that said US spy satellites had detected North Korea moving anti-ship cruise missiles to a patrol boat.
The Trump administration has made North Korea a top priority, with Tillerson announcing an global pressure campaign in April that U.S. officials and observers say is beginning to tighten the noose on Pyongyang.
A scheduled meeting on the sidelines of the summit between Mr Wang and his Vietnamese counterpart Pham Binh Minh was called off as Vietnam asked ASEAN foreign ministers to include in a communiqué its concerns about China's militarisation of land in the South China Sea.
But it remains cautious of triggering a North Korean collapse, fearful of fomenting chaos along its border or advancing any scenario that would lead to a reunified and US -allied Korea on its doorstep.
Within the framework of the resolution, the United Nations members would not be available to open joint ventures or cooperative entities with North Korean entities or individuals, as well as not to increase the number of North Korean workers already engaged in the projects on the territories of the member states. -South Korea drills begin.
They're only a tactic for getting Kim Jong Un's totalitarian government to end its missile advances and atomic weapons tests, and there is little evidence to suggest this newest round of economic pressure will be more successful than previous efforts.
But Pak expressed skepticism toward a potential meeting between the two ministers, while Ri continued to evade repeated questions from the press.
"We're not going to give someone a specific number of days or weeks", Tillerson said.
Ri highlighted Pyongyang's fears of invasion by the USA, saying that only nuclear-armed countries have been safe from military actions by Washington. As it stands, it does not look like North Korea will budge on US and United Nations demands. The sanctions could further choke North Korea's struggling economy by slashing its $3 billion annual export revenue by a third.