"Should drought conditions persist, the food security situation is likely to further deteriorate."
North Korea is still recovering from a deadly famine in the late 1990s, and the UN's World Food Programme estimates 70% of the country's 25 million people still don't eat a "sufficiently diverse diet."
Now a prolonged period of dry weather, falling over North Korea's important growing season of April to June, has put their staple crops of rice and maize at risk.
During that period, rainfall in some of the key growing regions was half the long term average.
"Seasonal rainfall in main cereal producing areas have been below the level of 2001, when cereal production dropped to the unprecedented level of only two million tonnes," Vincent Martin, FAO representative in China and North Korea, said in a statement.
Long history of food shortages
Millions of tons of food aid was sent to North Korea for years from countries around the world to avoid an even larger death toll.
"There's a chronic shortfall of food (in North Korea) ... In terms of being able to feed their people, they never recovered," Jean Lee, global fellow at Wilson Center, told CNN.
Lee said any further food shortage would fall during North Korea's lean season, during the time between harvests.
"Then on top of the drought, they may get some monsoon flooding when it does start to rain. So this country that has very little arable land, 85% mountains (has a) vicious cycle of drought and flooding," she said.
The UN organization called for immediate assistance for the country's farmer and general population, including irrigation equipment and food aid.
"(Furthermore), it is recommended to introduce longer-term measures to increase farm and household resilience to natural disasters and climate change," the report said, citing North Korea's susceptibility to natural disasters.
International pariah
North Korea and the international community have a long history of exchanging food aid for concessions in the rogue state's weapons program.
Lee said there was likely to be a call from the UN's World Food Programme for donations to make up any shortfall in North Korea.
"It is very hard for governments to avoid linking aid to politics but generally speaking, most governments try to keep it separate," she said, adding the US sent flood assistance to North Korea in 2016.