U.S. Secretary of State Condoleezza Rice said Thursday she is “cautiously optimistic” that it may be possible to start implementing a September 2005 agreement on ending North Korea's nuclear weapon programs. “I am cautiously optimistic that we may be able to begin, again, to implement the joint statement of 2005 toward the denuclearization of the Korean Peninsula,” Rice told the Senate Foreign Relations Committee. Six-nation talks among the two Koreas, the United States, China, Japan, and Russia resumed on Thursday in Beijing, and South Korean officials said North Korea was willing to take initial steps toward ending its nuclear weapons program. The talks in September 2005 produced an agreement under which North Korea said it was committed “to abandoning all nuclear weapons and existing weapons programs.” In return, the five other countries offered economic, political, and security incentives.