He added that the USA will resolve North Korea's problem alone if China does not help rein in Pyongyang's nuclear aspirations.
"If the USA makes a pre-emptive strike on North Korea, Pyongyang will attack South Korea, Japan and the United States forces stationed in the two countries", Li wrote.
The U.S. strike could include missiles and bombs, cyber and special operations on the ground. The U.S. military then dropped a weapon nicknamed the "mother of all bombs" on the Islamic State in Afghanistan.
As the USA continues to publicly weigh options to contain the country and its nuclear ambition, Han said North Korea would not simply stand by if it believed Trump would follow through on his threats.
He says another nuclear test would invite tougher measures from Beijing, possibly including new restrictions on Chinese companies' investments in North Korea and cuts in the number of Chinese tourists allowed to visit.
Many experts believe North Korea could have a viable nuclear warhead and a ballistic missile capable of hitting the USA mainland within the next few years.
South Korea's top diplomat said today that the USA would consult with Seoul before taking any serious measures.
DPRK stands for the North's official name, the Democratic People's Republic of Korea. "In fact, the U.S.is working to reassure us that it will not, just in case that we might hold such concerns".
"Two things are coming together this weekend", said retired Adm. James Stavridis, former commander of North Atlantic Treaty Organisation and an NBC analyst.
He diverted the Carl Vinson aircraft carrier and its strike group towards the Korean peninsula last weekend in a show of force.
Many observers have linked these celebrations with a possible nuclear weapons test. "We are trying to communicate our level of concern and the existence of many military options to dissuade the North first".
"Right now we all must stop at the edge of the abyss and not take this fateful step", he said.
"The Trump administration, which made a surprise guided cruise-missile strike on Syria on April 6, has entered the path of open threat and blackmail", the North's KCNA news agency quoted the military as saying in a statement.
President Donald Trump tweeted on Tuesday that "North Korea is looking for trouble".
A top North Korean official is accusing the Trump administration of wanting to "annihilate" the country. Russian Federation and China are critical to any pressure campaign on North Korea because they both hold veto power on the U.N. Security Council.
Implementation of the preemptive USA plans, according to multiple US officials, depends centrally on consent of the South Korean government.
It says North Korea will face strong punishment it will find hard to withstand if it makes a significant provocation, such as another nuclear test or an intercontinental ballistic missile launch.
"The bottom line is that North Korea has an improving nuclear weapons arsenal", said David Albright, the institute's president.
North Korea marks the 105th anniversary of the birth of the state founder Kim Il Sung on Saturday and in 2012 launched a long-range rocket carrying a satellite to mark the date.
If China decides to help, that would be great.
"I think that is what President Trump is getting trying to get the Chinese to do", said Cha.
Russia's Deputy Foreign Minister Sergei Ryabkov warned the USA that attempts to rely on force to pressure North Korea will not help. "So that's why. It's not the DPRK but the USA and Trump that makes trouble", Mr Han said. It went on to warn of a "merciless retaliatory strike" following any action by the U.S.