The US nuclear envoy made the remarks during a joint press conference in Seoul with his Republic of Korean counterpart Lee Do-hoon. He arrived in Seoul on December 15 for a three-day visit.
"It is time for us to do our jobs. Let's get this done. We are here and you know how to reach us," said Biegun to the DPRK.
"The US does not have a deadline. We have a goal to fulfill the commitments the two leaders made during their historic summit meeting in Singapore," he noted.
His remarks came amid the deadlocked denuclearization negotiations between Pyongyang and Washington.
The DPRK and the United States held working-level denuclearization talks in Stockholm in October, but it ended without progress. Pyongyang set its deadline for the denuclearization negotiations at the end of this year.
The DPRK Chairman Kim Jong Un and US President Donald Trump held the first-ever DPRK-US summit in Singapore in June last year, agreeing to seek the complete denuclearization of and the lasting peace settlement on the Korean Peninsula.
Kim and Trump met again in the Vietnamese capital of Hanoi in late February, but it ended without progress. In an impromptu meeting in late June at the inter-Korean border village of Panmunjom, the two leaders agreed to resume working-level negotiations.
