South Korea's Unification Minister Cho Myoung-gyon says Seoul and Washington partially differ on the two Koreas' joint field study to connect their railways.

At a parliamentary audit Monday, Cho, however, said the U.S. is not opposed to the inter-Korean project, adding the two sides continue to consult on the issue with cooperation from Washington.

At their high-level talks earlier this month, the two Koreas agreed to conduct joint research in North Korea starting late October, but a delay in announcing the dates have spurred speculation the U.S. may have put the brakes on the initiative.

When asked about declaring a formal end to the Korean War and North Korean leader Kim Jong-un's visit to Seoul within the year, the minister said involved parties continue to make efforts to meet the goals by the year's end.

Cho also said the Red Cross from the two Koreas plan to seek ways to hold more reunions of war-separated families at the North's Mount Geumgang sometime next month.