The United States is demanding that North Korea "must stop its provocative and escalatory behavior" after President Donald Trump stepped up his warnings against Pyongyang and spoke with his Chinese counterpart Xi Jinping by phone.
Meanwhile, US military forces "stand ready" to safeguard Guam after the North threatened to fire ballistic missiles toward the American Pacific island territory, the White House said.
It said Trump "reassured" Guam Governor Eddie Calvo in a phone call that the US military would "ensure the safety and security of the people of Guam, along with the rest of America."
During their separate call, Trump and Xi also hailed the adoption of a United Nations Security Council resolution targeting the North as an "important and necessary step toward achieving peace and stability on the Korean Peninsula," a White House statement read.
"The presidents also reiterated their mutual commitment to denuclearization of the Korean Peninsula," it added, stressing the two leaders had an "extremely close relationship" that "will hopefully lead to a peaceful resolution of the North Korea problem."
"President Trump and President Xi agreed North Korea must stop its provocative and escalatory behavior," the statement read.
It said Trump looks forward to a "very historic" meeting with Xi in China later this year.
President Xi Jinping, in a call with President Donald Trump, said all sides should avoid rhetoric or action that would worsen tensions on the Korean Peninsula, Chinese state media said.
China Central Television on Saturday cited Xi as saying that Beijing and Washington are both interested in the denuclearisation of the peninsula.
The report quotes Xi as saying: "At present, the relevant parties must maintain restraint and avoid words and deeds that would exacerbate the tension on the Korean Peninsula."
Trump has pushed China to pressure North Korea to halt a nuclear weapons program that is nearing the capability of targeting the United States. China is the North's biggest economic partner and source of aid, but says it alone can't compel Pyongyang to end its nuclear and missile programs.