Korean peace talk participants met in Geneva

GENEVA (CNN) -- Four-party talks aimed at implementing permanent peace on the Korean Peninsula opened Wednesday for the first time in seven months.

Negotiators from South and North Korea, as well as their respective backers in the 1950-53 Korean War, the United States and China, are involved in the closed-door talks in Geneva, which are scheduled to last until Sunday.

Diplomats hold out little hope for quick progress in the Korea talks after the previous round in March broke up in disarray with the United States and North Korea trading charges of failure and China putting the blame on both sides.

North Korea has repeated its demand for the withdrawal of 37,000 U.S. troops from South Korea -- repeatedly rejected by Washington.

South Korean Ambassador Pak Kun-woo, who will chair the session, told reporters no agenda had been agreed on yet, but declared: "The four-party talks have great importance for peace and stability in and around the Korean Peninsula. I'll do my utmost to move forward the session."

Jakob Kellenberger, the Swiss secretary of state for foreign affairs who is hosting the talks, proposed opening a humanitarian corridor across the demilitarized zone to ease the flow of aid to the North, which has been coping with massive hunger.

Reuters contributed to this report.