WASHINGTON (REUTERS) - White House national security adviser Robert O'Brien said the United States had reached out to North Korea seeking to resume talks, according to an interview published on Sunday (Jan 12) by Axios news website.

Mr O'Brien also said it was a "positive" sign that North Korean leader Kim Jong Un had not delivered on a warning of a "Christmas gift".

Some analysts had said it might be a sign Pyongyang was preparing a long-range missile test, while US President Donald Trump said last month that the gift "might be a beautiful vase".

"We've reached out to the North Koreans and let them know that we would like to continue the negotiations in Stockholm that were last undertaken in early October," Mr O'Brien told the online news site last Friday.

"We've been letting them know, through various channels, that we would like to get those back on track," he added.

A spokesman for the National Security Council did not immediately comment on Sunday.

Last Saturday, North Korea said it had received birthday greetings for Mr Kim from Mr Trump, but their personal relationship was not enough for a return to talks, according to a statement published by state news agency KCNA.

Mr Trump relied on his personal rapport with Mr Kim to push for denuclearisation in talks in 2018 and 2019, but those efforts have largely failed at the working level and sparked new concerns about Pyongyang's nuclear capabilities.

North Korea will not discuss proposals such as those Mr Trump made at his last summit with Mr Kim in Hanoi in February 2019, a Foreign Ministry adviser said last Saturday.

Mr Kim said recently that there were no longer grounds for Pyongyang to be bound by a self-declared moratorium on intercontinental ballistic missile and nuclear bomb testing and that a "new strategic weapon" would be introduced in the near future.

South Korean President Moon Jae-in said recently there was an urgent need for practical ways to improve ties with North Korea, adding he was ready to meet its leader in North Korea.