North Korea may undertake more nuclear activity as early as Saturday in response to Washington's talk of pre-emptive strikes on the rogue nation and the strategic deployment of a U.S. aircraft carrier.
Every year on April 15, Pyongyang celebrates the birthday of its founding father Kim Il-sung, the grandfather of current leader Kim Jong-un, with parades and drills showing off military hardware. This year, festivities could take on a nuclear element as Kim looks to assert power following President's Trump's tough stance on his country.
"It is highly likely that North Korea would engage in some form of provocation, another missile launch or even a sixth nuclear test, on or around April 15," Shawlin Chaw, senior analyst at Control Risks, told CNBC.
"The DPRK (Democratic People's Republic of Korea) has stated it is ready for war in response to the U.S. show of force this week and will most likely use the politically sensitive date to retaliate and reinforce its legitimacy with its own people," Chaw said, referring to the USS Carl Vinson's recent move.
North Korea has only demonstrated military action twice on April 15 in recent years. In 2012, it launched a long-range rocket carrying a satellite and last year, it tested an intermediate-range missile that reportedly failed.
To mark the national day, around 200 foreign journalists were in Pyongyang, Reuters reported on Thursday.
Kim Jong-un needs to appear strong to his own people on April 15, especially in the context of perceived foreign bullies bringing their warships into the region, explained Steven Ward, assistant professor at Chosun University.
"But a missile test isn't Kim's only option. A less provocative choice might be an underground nuclear test," he said.
On Wednesday, commercial satellite imagery of the nation's Punggye-ri Nuclear Test Site revealed "continued activity around the North Portal, new activity in the Main Administrative Area, and a few personnel around the site's Command Center," U.S. think-tank 38 North said on its website.
That same day, Trump and Chinese President Xi Jinping spoke to each other via telephone about the "menace of North Korea," according to a tweet from the president, who also said Washington was prepared to deal with the pariah state without China, if necessary.
Historically, this time of the year tends to be particularly active for Pyongyang's nuclear experiments. Joint military exercises between Seoul and Washington, which kicked off March 1, in addition to April 15, are signature opportunities for Kim to show off technological advancements.
And if nothing happens on April 15, that could mean Kim has another occasion in mind.
"The back up date may be April 25, the foundation day of guerrilla forces launched by KIS, which became the Korean People's Army," John Park, Asian security analyst at Harvard Kennedy School, told CNBC.
Beijing and Seoul have already agreed to impose new sanctions on Pyongyang if it attempts further nuclear or long-range missile tests. But the international response could vary depending on what happens, Park explained.
"If Kim conducts a sixth nuclear test, the likely response from the core countries — U.S., China, South Korea, Japan — would be more sanctions and yet another U.N. Security Council resolution condemning the DPRK."
But things could get more serious if Kim were to launch a long-range ballistic missile that's determined to be on a trajectory toward Japan or U.S. territory.
"A military capability in the USS Carl Vinson carrier group that wasn't fully operational/effective in the early 2000s would come front and center," Park said, referring to the Aegis ballistic missile defense system that's installed on two destroyers and one cruiser accompanying the Vinson.
"Japan has already sent its naval vessels equipped with this system to join the carrier group. Under this scenario, the probability is the highest for a kinetic event. The U.S. and Japanese navies would attempt intercept DPRK inbound ballistic missiles," Park said.