Unification Minister Chung Dong-young has discussed North Korea's nuclear issue with U.S. State Secretary Colin Powell in Washington.

During their meeting Tuesday, Chung stressed that the fourth round of six-way nuclear talks should take place at the end of this month as scheduled in order to maintain the momentum to seek a peaceful resolution to the 23-month-old nuclear standoff.

Chung said that, in order to keep the talks' momentum going, patience and concessions are necessary on the part of participants in the multilateral discussions.

Ahead of meeting Powell, Chung met Assistant State Secretary James Kelly, the U.S. chief delegate to the six-party nuclear negotiations.

Later in the day, Chung also talked with Defense Secretary Donald Rumsfeld. Rumsfeld thanked South Korea for sending additional troops to Iraq to help with the U.S.-led coalition in the war-torn country.

Rumsfeld pledged U.S. cooperation following Chung's request for Washington to share intelligence with Seoul to guard against possible acts of terrorism against South Korean troops and nationals following its military deployment in Iraq.

Chung arrived in Washington on Tuesday and is set to return home on Friday.