Earlier in the week, following his meeting with Chinese President Xi Jinping, Trump said the USA would take unspecified action against North Korea if Beijing doesn't cooperate.
McMaster said President Donald Trump has made clear he will not allow the nuclear-armed Pyongyang regime to put the USA and its regional allies under threat. What appeared to be new long-range ballistic missiles were on display in the parade.
U.S. President Donald Trump acknowledged China's help with the North Korean issue on Sunday, linking it to a softer line taken on China's management of its currency.
On Friday, North Korea said the unsafe security situation was due to the "Trump administration's reckless military provocation".
North Korea has the world's fourth-largest standing army, and could respond to a US attack by launching conventional, chemical, or nuclear weapons against South Korea or Japan, where several American military bases are located.
There was no need for the USA military to shoot down North Korea's anniversary salvo - the missile failed at launch. But the failure will sting in Pyongyang because it comes a day after one of the biggest North Korean propaganda events of the year- celebrations of the 105th birthday of late North Korea founder Kim Il Sung, the current leader's grandfather.
The U.S. nuclear-powered Carl Vinson aircraft carrier strike group is also heading to the region.
National Security Advisor H.R. McMaster said in a television appearance that the U.S.
Indeed, while the latest missile exploded soon after launch, experts say North Korea is able to learn from its mistakes and hone its technology.More news: South Korea: North Korean missile test fails
A feared military confrontation between North Korea and the United States didn't materialize over the weekend, but tensions between the two countries remain dangerously high for the indefinite future.
After months of labelling China "currency manipulator", Mr Trump's softer rhetoric towards Beijing comes as the United States tries to foster warmer relations in an effort to ease tension on the Korean peninsula. "Let me assure you, under President Trump's leadership, our resolve has never been stronger". We will see what happens!
Sinpo is the site of a North Korean submarine base and where the North has previously tested a submarine-launched ballistic missile it is developing.
More directly on North Korea, the president returned to a theme of placing much onus on China for reining in the North.
During a brief interaction with members of the public, a Western press delegation was asked to avoid the topic of the failed missile launch, as well as any discussion of global politics or the North Korean leadership.
Pence addressed that head-on at the U.S. Army Garrison Yongsan only hours later while speaking to U.S. soldiers as they sat down for their Easter dinner. China's customs department issued an order on April 7 telling traders to return North Korean coal cargoes, trading sources said.
The North has a habit of firing off missiles to mark major political anniversaries, or as gestures of defiance to top United States officials visiting the region.
Washington sees North Korea's pursuit of nuclear weapons and ballistic missiles as a threat to world security and to its Asian allies, Japan and South Korea.
A White House foreign policy adviser traveling with Pence said no US response to the missile launch was expected because there was no need for the U.S.to reinforce the failure.
After the USA launched cruise missiles at a Syrian airbase and "the mother of all bombs" over territory held by "Islamic State" militants in Afghanistan, some analysts have warned that the U.S. may also take military action against Pyongyang.