North Korea has conducted a test of a new high-thrust engine at its Tongchang-ri rocket launch station. He said Xi and US President Donald Trump must have more talks as he assured that the president of the free world recognised "very high value" on interactions with the Chinese president.
Trump, who traveled to his Mar-a-Lago resort this weekend, said he discussed North Korea's missile launches during weekend meetings.
Chinese Foreign Minister Wang Yi pushed back against the tougher US line on North Korea, reiterating his country's view that the only way to rein in its reclusive neighbor is through talks.
North Korea formally insists the rockets are for its space program.
Retired Lt. Gen. Mark Hertling, a CNN analyst, said the improvements of the rockets could help North Korea develop intercontinental ballistic missiles.
The United States has long called on China to do more to rein in its ally, North Korea.
During Tillerson's visit to China, the two sides said they would work together to try to make North Korea take "a different course".
China has also been infuriated by the deployment of an advanced US anti-missile system in South Korea, which it says will both harm China's own security and do nothing to ease tensions.
The Japanese government said three out of four missiles launched from North Korea on March 6 landed in the sea less than 200 nautical miles (around 370 kilometers) from Oga.
Tillerson told South Korean officials Sunday that a new range of security and diplomatic measures are being explored, Express reports. Russian Federation also opposes the system, for the same reasons.