South Korea and the United States agree on the urgent need to address the challenges posed by North Korea, South Korean Foreign Minister Park Jin said Tuesday.

The South Korean diplomat said he and his US counterpart, Antony Blinken, have also agreed on the importance of maintaining and strengthening US extended deterrence to South Korea.

"(We) agreed that the North Korea issue is the top policy priority for both South Korea and the US under the serious current condition where questions about North Korea's seventh nuclear test and its use of tactical nuclear weapons are being raised," Park said while meeting with reporters here.

His remarks came one day after he held a meeting with his US counterpart, the first of its kind since Park came into office last month.

In a joint press conference after their meeting here on Monday, both Park and Blinken noted the North may have completed all preparations for a nuclear test and may only be waiting for a political decision from its leaders.

North Korea conducted its sixth nuclear test in September 2017.

"Secretary Blinken and I have agreed on the importance of (US) extended deterrence amid North Korea's continuing provocations," Park said.

North Korea has launched at least 31 ballistic missiles so far this year, which already mark the largest number of ballistic missiles fired in a single year, according to US officials.

South Korea and the US will push for fresh U.N. Security Council sanctions against North Korea should Pyongyang go ahead with its feared nuclear test, Park said.

A senior South Korean official said the countries have also agreed to consider imposing unilateral sanctions if necessary.

The US sought to push through a Security Council resolution on North Korea last month, but it was blocked by two permanent members of the Council -- China and Russia.

"Should North Korea stage additional provocation, especially a nuclear test, we believe China and Russia may be left with no reason to oppose (a Security Council resolution)," the official said, while speaking on condition of anonymity.

"With regard to unilateral sanctions, the countries (South Korea and the US) have agreed to review various steps and implement them (when necessary)," the official added.

Park on Monday said the allies have agreed to restart their strategic dialogue on extended deterrence, known as Extended Deterrence Strategy Consultation Group (EDSCG), at the earliest date possible.

Blinken reaffirmed the talks may be held in "weeks ahead."

Park reiterated that the allies continue to remain open to dialogue with North Korea.

"At the same time, Secretary Blinken and I reaffirmed that the door to dialogue with North Korea will always remain open," Park said.

"Secretary Blinken and I also had in-depth discussions about COVID-19 outbreak in North Korea. South Korea and the US remain sincerely committed to helping North Korea deal with its COVID-19 outbreak. I wish the North would quickly respond to our offer," he added.

North Korea has avoided dialogue with South Korea and the US since late 2019.

Blinken earlier said the North also remains unresponsive to US overtures to date. (Yonhap)