North Korea tested what its leader Kim Jong Un described as "a new birth" of the country's rocket industry, state media reported on Sunday.
Kim's nuclear bomb test site is also almost ready for a new blast, according to satellite images shared by Pyongyang watchdog 38 North.
Tillerson is pushing for closer China-U.S. cooperation on dealing with the growing threat from North Korea's nuclear weapons program.
It staged its two latest nuclear tests past year and recently fired off missiles which it described as practice for an attack on US bases in Japan, in a challenge to US President Donald Trump.
A North Korean military unit tasked with striking USA bases in Japan was involved in those launches, the state news agency said.
For his part, Tillerson struck a more conciliatory tone in Beijing than he had a day earlier in Seoul, stressing that Beijing and Washington shared a "common view" that North Korea must be stopped.
Kim at that time hailed the test and called for more rocket launches to turn the country into a "possessor of geostationary satellites in a couple of years to come".
Outside observers say the nuclear-armed Pyongyang's space programme is a fig leaf for military use, as rocket engines are easily re-purposed for missiles.
After talks with his counterpart Wang Yi on Saturday, Tillerson warned that regional tensions had reached a "dangerous level".
It test-fired four missiles into seas off Japan last week as the US and South Korea began annual military drills that the North claims are rehearsals for invasion.
However, the regime has reportedly refused to scale down its missiles tests.
The test was conducted at the North Korea's northwest facility, where the country has been launching rockets to put satellites into orbit, the Korean Central News Agency said on Sunday.
The North Korean Embassy counsellor in Malaysia, Kim Yu-song, expressed his anger and asked the media not to take pictures of him putting bins in front of the embassy this evening.
In Seoul, he warned that the USA would consider preemptive military action if the threat reaches a level "that we believe requires action". "We hope all parties, including our friends from the United States, could size up the situation in a cool-headed and comprehensive fashion and arrive at a wise decision".