President Donald Trump says he and South Korean President Moon Jae-in (jah-yihn) have discussed North Korea in their latest call.
The leaders also called on the North to refrain from any more provocations, warning they will only lead to its isolation and eventual collapse, according to Park Soo-hyun, spokesman for South Korea's presidential office Cheong Wa Dae.
Responding to a question, Mattis said he is not aware of any effort on the part of South Korea to shoot down the North Korean missile.
The conservation came two days after North Korea's latest ballistic missile launch, in which the projectile again flew over Japan's airspace.
In a unanimous statement backed by China, the council said the launch was carried out just three weeks after a first missile overflew Japan and less than two weeks after Pyongyang´s sixth and biggest nuclear test.
McMaster called for "rigorous enforcement" by all United Nations member states of UN sanctions on North Korea, including the latest package that for the first time capped oil supply to the country, as a way of compelling it to alter its provocative behavior.
China will implement all United Nations Security Council resolutions, "no more, no less", Cui Tiankai, China's ambassador to the USA, told reporters at a briefing in Washington when asked if China would cut oil shipments.
The South Korean leader underscored the importance of enhancing South Korea's own defense capabilities, along with those of the joint forces of South Korea and the United States.
"America and our allies will never be intimidated".
Mr Cui said the United States, not China, needed to take more responsibility for the issue. The South Korean president is set to attend a trilateral summit with Trump, and Japanese Prime Minister Shinzo Abe on Thursday.
Trump has also threatened "fire and fury" in response to North Korea's threats.
"The two leaders noted that North Korea continues to defy the worldwide community, even after the United Nations strongly condemned North Korea's repeated provocations twice in the past week", it said.
According to Cheong Wa Dae, President Moon Jae-in and US President Donald Trump agreed to cooperate more closely and to work with the worldwide community to further raise the pressure on Pyongyang.
Donald Trump let loose on Twitter Sunday with a shoot-from-the-hip volley of posts referring to North Korea's leader Kim Jong-Un as "Rocket Man" - and picturing himself taking out Hillary Clinton with a golf ball.
"I personally think he slaps the right people, he hugs the right people, and he comes out with (the) U.S. being very strong, in the end", Haley, speaking at the White House, said of Trump's speech.