Attempts by President Joe Biden's administration to reach out to North Korea have so far been met with silence, a senior US official said on Monday.
"We reached out to the North Korean government through several channels starting in mid-February, including in New York. To date, we have not received any response from Pyongyang," the administration official said, asking not to be identified.
The official said Washington was hoping to make contact with Pyongyang "to reduce the risks of escalation" in their tense standoff across the divided Korean peninsula.
During his one-term presidency Donald Trump made extraordinary overtures to North Korean dictator Kim Jong Un, meeting him three times in a bid to negotiate an end to the isolated state's nuclear weapons' arsenal.
However, the two summits and a surprise visit by Trump over the border between South and North Korea proved fruitless.
The Biden administration official said there has now been "over a year without active dialogue with North Korea, despite multiple attempts by the US to engage."
A major review of US policy is now underway to evaluate the "increasing threats" posed by North Korea, the official said.
"Throughout the review process, we have and will continue to engage with our Japanese and South Korean allies to solicit input and explore fresh approaches."