Pyongyang claimed on Monday that the missile it fired over the weekend was a "new ground-to-ground medium long-range strategic ballistic rocket" capable of carrying "a large, heavy nuclear warhead".
Asked about the possibility of the United States having carried out cyberattacks to thwart Pyongyang's past missile launches, Han gave a negative answer.
The official North Korean news agency KCNA said it flew 787 kilometers and reached an altitude of 2,111 kilometers. "South Korea and Japan have been watching this situation closely with us", Spicer continued.
US President Donald Trump warned in an interview with Reuters this month that a "major, major conflict" with North Korea was possible.
South Korean Defence Minister Han Min-koo told parliament Sunday's test-launch was "successful in flight".
The test missile reportedly flew more than 430 miles and reached an altitude of 1,245 miles before landing in the sea between North Korea and Japan, demonstrating that it could be used to target USA military bases in the Pacific.
North Korean news reports are often exaggerated - Pyongyang has threatened for decades to reduce Seoul to a "sea of fire", for instance - but Monday's claim, if confirmed, would mark another advance toward the North's goal of fielding a nuclear-tipped missile capable of reaching the USA mainland.
UN Secretary-General Antonio Guterres condemned Pyongyang over Sunday's launch, saying its defiance of UN resolutions was "a threat to peace and security in the region".
Two senior national security advisers to Trump will meet Moon's top foreign policy adviser, Chung Eui-yong, in Seoul on Tuesday to discuss a summit of the leaders and the North's missile test, a source with direct knowledge of the meeting said.
The test is also an immediate challenge to South Korea's new leader, Moon Jae-in, a liberal elected last week who expressed a desire to reach out to North Korea. Second, it would also reduce the likelihood that any new ballistic missile launch testing ICBM components will turn into an global crisis.
The advancement in North Korea's missile technology puts pressure on Japan. Its capabilities fall in between those of intercontinental ballistic missiles, whose speed at re-entry is said to reach Mach 24 or faster, and the midrange Musudan missiles, which have a range of 2,500km to 4,000km.
Leader Kim Jong Un personally oversaw the test on Sunday, the official Korean Central News Agency (KCNA) said, and pictures by state media showed him gazing at the missile in a hangar before the launch.
"This is the longest-range missile North Korea has ever tested", Jeffrey Lewis of the Middlebury Institute of International Studies told AFP.
But aside from World Cup bids, North Korea is perhaps more preoccupied at the moment with its missiles tests and threatening the world with nuclear war.
Moon questioned, and then equivocated, on THAAD, but was given a campaign issue when Trump unexpectedly and unnecessarily suggested that South Korea pay for the USA system.
The Council has imposed six sets of sanctions against the North since 2006. The session had been requested by the United States and Japan on Sunday, shortly after North Korea's test launch of an intermediate-range ballistic missile.
However, given the Trump administration's bellicose rhetoric over preemptive strikes against North Korea intertwined with its "America First" isolationist tendencies, Seoul and Tokyo may not only face decoupling, but also what one could call a "reverse decoupling" problem. The USS Carl Vinson, an aircraft supercarrier, is also engaging with South Korean navy ships in waters off the Korean Peninsula, according to Seoul's Defense Ministry.