South Korea's foreign minister offered a note of caution ahead of six-nation talks to freeze North Korea's nuclear program, saying Wednesday there was a long way to go before a final agreement will be reached. Meanwhile, the nominee to be the No. 2 official at the US State Department said in Washington that "there are some grounds for optimism" for seeing results at the talks because of continued international pressure on the North Korean government. John Negroponte highlighted the US Treasury Department's moves to isolate Pyongyang from the international financial system for its alleged counterfeiting and money laundering, adding that such steps "can provide a bit of leverage" at the six-nation nuclear talks. The negotiations - which involve the United States, the two Koreas, China, Russia and Japan - are set to resume February 8 in Beijing.