I haven't been able to find any direct evidence, so this is a bit of me reading between the lines.
From the Visa Waiver site it states that people who would normally use the VWP, but have been to North Korea since 2011 can no longer use the VWP and must instead apply for a business or tourist visa.
Under the Visa Waiver Program Improvement and Terrorist Travel
Prevention Act of 2015, travelers in the following categories must
obtain a visa prior to traveling to the United States as they are no
longer eligible to travel under the Visa Waiver Program (VWP):
Nationals of VWP countries who have traveled to or been present in Democratic People's Republic of Korea, Iran, Iraq, Libya, Somalia,
Sudan, Syria, or Yemen on or after March 1, 2011 (with limited
exceptions for travel for diplomatic or military purposes in the
service of a VWP country).
Nationals of VWP countries who have traveled to or been present in Cuba on or after January 12, 2021 (with limited exceptions for
travel for diplomatic or military purposes in the service of a VWP
Nationals of VWP countries who are also nationals of Cuba, Democratic People's Republic of Korea, Iran, Iraq, Sudan, or Syria.
This means that simply traveling to NK does not automatically ban you from coming to the US.
However, Canadians don't use the VWP to enter the US (except for corner cases like are meeting family in the US), but I haven't been able to find out what that means for a CA citizen being a tourist in NK, but I guess that it also means applying for a visa.
But .... You mentioned coming to the US for work. That will mean you have to apply for a non-tourist/non-business visa which probably puts you in the same boat as VWP who have visited NK.
So while you will be scrutinized for your trips, I don't see it as an automatic failure to have visited NK.
Finally, NK doesn't allow independent tourism in the first place, so you will have to be a part of an organized tour group in order to visit NK.
But (there are always buts), this Australian government site says that tours to NK have been suspended:
- You can only travel on an official tour. An official guide must always accompany you. Charges for travel can be high, including for
taxis, guides, tolls and permits.
- Tours have been suspended until further notice. If it becomes safe to
travel to North Korea, you'll probably have to travel via Beijing. Get
a double-or multiple-entry visa for China. Otherwise, you won't be
able to re-enter China when you leave North Korea. Contact the Embassy
or Consulate of the People's Republic of China for details.
I have no idea how true the suspension is, but this random NK tour site says:
NOTICE: The North Korea border is currently closed due to the
Coronavirus pandemic. Please check COVID-19 & North Korea for updated
N0 Tours to North Korea (DPRK) will be taking place until the border
is open again - the tours below are planned departure dates but until
the country is open to tourists again all tours will remain suspended
(gotta love the N0 typo, that's a zero, not the letter "O"! That was them, and not me.)
And for fun, here is the CA travel advice to NK (which you probably already know about):
NORTH KOREA - AVOID ALL TRAVEL
Avoid all travel to North Korea due to the uncertain security situation caused by its nuclear weapons
development program and highly repressive regime.
There is no resident Canadian government office in the country. The
ability of Canadian officials to provide consular assistance in North
Korea is extremely limited.