Trump warned North Korea on Tuesday that any United States military action against North Korea would be "devastating" for Pyongyang, but said the use of force was not Washington's first option.
The UN North Korea sanctions committee has scaled up a list of conventional arms dual-use items whose supply, sale or transfer to North Korea is wholly barred in compliance with Resolution 2371, adopted early last month in the wake of the North's ICBM tests, a USA broadcaster reported Tuesday.
Tillerson's visit comes at a time of high tension between the United States and North Korea, which is working to develop nuclear-armed missiles capable of reaching the USA mainland.
On Tuesday, the US Treasury announced sanctions against 26 more individuals as part of its non-proliferation designations for North Korea, as well as nine North Korean banks, including some with ties to China.
In August Beijing ordered a blanket ban on imports of coal, ores and seafood...
US experts said Beijing's coal imports in August highlight its unwillingness to stick to promises to cut trade with Pyongyang.
U.S. wants diplomatic fix for North Korea crisis: Mattis
There also existed the risk that obsolete North Korean interceptor aircraft could have crashed during a night flight, he added.
Nauert called China's steps to implement tougher United Nations sanctions on North Korea after its recent missile and nuclear tests "significant".
Anthony Ruggiero, a senior fellow at the Foundation for Defense of Democracies, said the development "shows that China is not a reliable partner". In reply, White House press secretary Sarah Huckabee Sanders strongly denied that the US had declared or planned to declare war on North Korea.
An experienced trader who handles coal from North Korea said his 5,000-ton cargo was allowed through customs last month after being stuck at a Chinese port for six months.
Police said the North Korean hackers, pretending to be security authorities, sent emails containing malware between July and August this year, according to Yonhap.
At the United Nations on Monday, North Korean Foreign Minister Ri Yong Ho accused Trump of declaring war on North Korea and threatened that Pyongyang would shoot down US warplanes flying near the peninsula.