A senior U.S. diplomat says progress was made during recent talks with North Korea over resuming the stalled nuclear disarmament negotiations, but added that the impasse remains.

U.S. Assistant Secretary of State Kurt Campbell made the remarks Thursday in Seoul, where he briefed officials about the second round of direct bilateral talks between American and North Korean officials in Geneva. Campbell told reporters “there were no breakthroughs,” and no decisions have been made about a new round of talks.

The six-nation nuclear talks, involving the two Koreas, China, Japan, Russia and the United States, were aimed at convincing North Korea to abandon its nuclear program in exchange for massive economic aid. Pyongyang walked away from the talks in April 2009, and later conducted its second nuclear weapons test and several long-range missile tests.

North Korea now says it wants to resume the talks, but without preconditions set by the U.S. and South Korea, including a suspension of its uranium enrichment program.