A Russian lawmaker who just returned from a visit to Pyongyang has said North Korea is preparing to launch another missile "in the nearest future".
Anton Morozov, of the nationalist Liberal-Democratic Party, added that he has seen calculations showing the missile can hit the US West Coast, the Daily Mail reports.
Morozov also said the North Koreans told him they have technology that would allow them to bring a warhead back down to earth intact.
The Party Foundation Anniversary, in which North Koreans celebrate the founding of their ruling communist party, is due to take place on Tuesday next week.
Monday is also Columbus Day in the US, meaning any potential launch would be very likely to happen on either of those two days.
Kim Jong Un usually times missile tests to coincide with American public holidays to ensure maximum media coverage.
The last major test conducted on a public holiday was a missile launch on the 4th of July, which Kim said was "a gift for the American bastards".
The news comes after President Trump discussed the North Korean situation with military leaders on Thursday, describing the moment as "the calm before the storm".
When quizzed by reporters about what he meant, Trump said: "You'll find out".
The news also comes after Kim threatened to tame Donald Trump "with fire" after the President threatened to "totally destroy" North Korea in a speech to the UN.
In an unprecedented personal address to President Trump, Kim said the US would "pay dearly" adding that North Korea "will consider with seriousness exercising of a corresponding, highest level of hard-line countermeasure in history".
He added: "I am now thinking hard about what response he could have expected when he allowed such eccentric words to trip off his tongue.
"I will surely and definitely tame the mentally deranged US dotard with fire."
North Korea has previously released images of what it claimed was a 'fire plan' for an attack on the US military base on Guam.
Kim was said to have reviewed the plans but decided not to attack.
Few international observers believe the North would actually attack the US or an allied country because there is no possibility it could win a war with America.
But Ri Yong Ho, North Korea's Foreign Minister, raised another prospect - that the hermit nation could land a warhead in the Pacific Ocean.
Such a demonstration would prove that they have a viable nuclear weapon, without necessarily prompting American military action.
Kim believes securing such a weapon, and proving to the international community that it works, is the key to ensuring his regime's survival.
Most experts agree that the North already has a missile capable of ranging most of the US, the Hwasong-14, which they have successfully tested multiple times.
Kim has also claimed to have a powerful hydrogen bomb that is small enough to fit on top of the missile, after the state carried out a sixth successful nuclear test earlier this year.
The final hurdle is in perfecting re-entry technology that would bring the warhead back to earth intact and on target.
It is not believed the North currently possesses this technology, as re-entry vehicles from previous Hwasong-14 tests were shown falling back into the ocean in flames.