Mattis made no mention of President Trump's decision to pull the USA out of the Paris climate change agreement.
The defense chief spoke directly to concerns that America might grant concessions to China in order to ensure its cooperation on North Korea, saying the issue was not "binary" and that the U.S. would continue to pressure Beijing elsewhere.
Dean says Russian Federation and China are both aware of the threats the North Korean weapons program could pose to peace, but the United States has "pushed the envelope" in this issue.
Speaking at an global security conference in Singapore, Mr Mattis said the Trump administration was encouraged by China's renewed commitment to working with the United States and others to rid North Korea of its nuclear weapons.
Speaking at the annual Shangri-La Dialogue here, US Defence Secretary General (Retd) James Mattis also said while competition between the US and China was bound to occur, the conflict between the world's two largest economies was not "inevitable".More news: Dikshit's remarks against Army chief 'absolutely wrong': Rahul
As tensions have increased between Pyongyang and Washington, the United States has been pressing China to rein in Kim Jong Un's nuclear programme. "Our two countries can and do cooperate for mutual benefit".
Earlier this week, the United States carried out a successful, first-ever missile defence test involving a simulated attack by an intercontinental ballistic missile, in a major milestone for a program meant to defend against a mounting North Korean threat.
Mattis said in Singapore on Friday that Washington stands with its Asia-Pacific partners and allies.
Russia, who historically is often a deciding factor in security council votes, condemned DPRK behavior, but not without voicing continued disapproval of USA military muscle flexing against North Korea.
North Korea on Sunday slammed the latest round of United Nations sanctions as "mean" and vowed to press ahead with its missile and nuclear weapons programs.More news: ICC Champions Trophy 2017
"The last-ditch gambling of the Trump administration for a nuclear war will only bring earlier the day when the US mainland will turn into ashes", said the spokesperson. "We consider it urgent", he added.
"The scope and effect of China's construction activities in the South China Sea differ from those of other countries in several key ways", Mattis told the Shangri-La regional defense summit in Singapore.
It was Washington's "ultimate double standard" to ban other countries from nuclear or missile tests amid its own attempts to modernize the USA arsenal.
The issue arose briefly during questions from his audience, but Mattis did not address it directly.
Haley said: "We want a negotiated solution, but North Korea must fulfill its basic obligations by first stopping all ballistic missile launches and nuclear weapons testing and taking concrete steps toward getting rid of its nuclear weapons program". Gen. Mattis avoided answering was repeatedly asked about Mr Trump's decision to pull out of the Paris pact.More news: McElroy | LeBron James isn't leaving the Cavaliers - yet
Japanese Defence Minister Tomomi Inada later said she placed "full trust" in the United States, a sentiment echoed by Australian Defence Minister Marise Payne.