"We do look at this as part of a pattern, and we respond in the way that we always have," White House press secretary Jay Carney said at a press briefing.
Unveiling detailed diplomatic goals for the new engagement policy with North Korea proposed by President Park Geun-hye, a high-ranking ministry official also brushed aside concerns about to what extent the U.S. will support the initiative by Park to expand inter-Korean relations, saying Washington "fully understands" the new approach by Seoul.
Park has pledged to pursue the "trust-building" policy with North Korea that calls for more engagement with the North, while, at the same time, not tolerating Pyongyang's nuclear ambitions.
In an annual policy briefing to Park on Wednesday, the foreign ministry summarized Park's initiative as a three-step approach in which South Korea will first provide humanitarian aid to North Korea while calling for the North to keep the agreements made with the South.
If the first-stage measure is successful in building confidence between the two Koreas, South Korea will expand inter-Korean economic cooperation without linking it to the North's nuclearization actions, the high-ranking ministry official said.
The third-stage step is for large-scale government assistance, but it will be possible only if North Korea demonstrates its sincerity for denuclearization through actions, the official said.
"From the start, the Korean Peninsula trust-building process does not link to North Korea's denuclearization," the official said on the condition of anonymity.
"If confidence is built throughout the first two stages, the third stage of large-scale assistance will be linked to progress in the North's denuclearization," the official said.
So far, the U.S. has maintained its stance that it won't return to nuclear talks with North Korea unless the North takes "irreversible steps" to denuclearize.
However, numerous analysts have raised doubts over Washington's so-called "strategic patience" approach toward North Korea, a policy of shunning direct talks with the North until it agrees to abide by past nuclear commitments.
Despite diplomatic efforts and international sanctions, North Korea has continued to develop its missile and nuclear programs.