However, the player's J-League club told Reuters on Friday they were confident Ryang would be added to North Korea's roster and would travel to South Africa next month.
"He missed the first application but we don't see any particular problem with him being added before (the final) deadline on June 1," a Vegalta Sendai official said on condition of anonymity.
Striker Jong Tae-se, dubbed "Asia's Wayne Rooney" by the media, will spear-head North Korea's charge in South Africa alongside fellow J-Leaguer An Yong-hak.
Kawasaki Frontale striker Jong will be North Korea's man to watch when Asia's mystery team tackle Portugal, Ivory Coast and World Cup co-favourites Brazil in Group G.
Forward Hong Yong-jo of Russian side Rostov is the only other member of the North Korean squad that is based outside the secretive communist state.
North Korea sent shockwaves around the world when they stunned Italy 1-0 to reach the quarter-finals of the 1966 World Cup in England.
They even took a three-goal lead against Portugal before losing 5-3.
North Korea face a baptism of fire against five-times winners Brazil in their Group G opener on June 15.
‘Maybe I’ll be signed by Wrexham, who knows? English football would suit me – if an offer came, I wouldn’t think twice, I’d go immediately’ Euro 2024 cult hero reveals his UK dream
‘Managing Leeds? It was an option that appeared, but it wasn’t the right timing. I decided it wasn’t a good idea to leave the club I was at mid-season’: Premier League boss admits to turning down opportunity to replace Jesse Marsch in 2023
