"When we refer to the Korean peninsula, the term encompasses the area of DPRK plus South Korean territory where U.S. nuclear weapons and other forms of aggression forces are deployed", the editorial said, using the initials of North Korea's official name, the Democratic People's Republic of Korea.
Stephen Biegun, the USA special representative for North Korea, made the announcement as he arrived in Seoul for four days of talks with South Korean officials.
With Washington doubling down on sanctions enforcement, humanitarian aid for North Korea has almost ground to a halt this year, despite warnings of a potential food crisis and improving relations with Pyongyang, aid groups say.
Despite the inaction, both Washington and Pyongyang have largely stuck to the vague script agreed to at the Trump-Kim Singapore summit in June, where Kim affirmed his "unwavering commitment to complete denuclearization of the Korean Peninsula" in exchange for American "security guarantees".
"The statement shows that North Korea is not necessarily on the same terms as the USA on the idea of denuclearization".
"We will also review American citizen travel to DPRK for purposes of facilitating the delivery of aid and ensuring that monitoring in line with worldwide standards can occur", Biegun said.
North Korean state media said removal of the U.S.'s nuclear weapons from the region was a condition of its own disarmament, raising the stakes for President Donald Trump's efforts to hold a second summit with Kim Jong Un.
Talks with Pyongyang have been delayed since a meeting between Secretary of State Mike Pompeo and North Korean official Kim Yong Chol was abruptly cancelled in November. The surprisingly blunt statement jars with Seoul's rosier presentation of the North Korean position and could rattle the fragile trilateral diplomacy to defuse a nuclear crisis that previous year had many fearing war.
South Korean Unification Minister Cho Myoung-gyon, who is due to meet Biegun on Friday, said the nuclear talks would face a critical moment between February and March.
"Measures, such as an end to the hostile policy toward North Korea and the lifting of unfair sanctions, are things the USA can do without lifting a finger, if they want to", the report said.
North Korean statements have repeatedly criticized the approach by Pompeo - Trump's point man on talks - and urged greater reciprocity from the US side. Washington and Seoul have not responded to the North Korean statement.
Lee and Biegun last met a month ago in Washington, when the two countries launched a working-level group to discuss North Korea issues. The meetings are likely to include conversations about a groundbreaking ceremony the Koreas plan to hold at the border village of Panmunjom next week for an aspirational project to reconnect their roads and railways.