WASHINGTON -- The United States on Friday underscored its commitment to finding the "best" way to secure "timely, accurate and unbiased" reporting on noncompliance with North Korea-related UN Security Council resolutions as a key sanctions monitoring panel was disbanded four months ago.

A State Department spokesperson made the remarks amid ongoing efforts among the US, South Korea, Japan and other countries to find an alternative to the UN expert panel whose mandate expired on April 30 due to Russia's veto of a resolution on its renewal.

"Russia's veto of the 1718 Committee Panel of Experts -- with China's tacit support through its abstention -- left a significant gap in reporting," the spokesperson said in response to a question from Yonhap News Agency.

"That is why the United States is actively working with all stakeholders to identify the best way forward to ensure timely, accurate, and unbiased reporting on noncompliance with DPRK-related UN Security Council resolutions is provided to the international community," the official added.

DPRK stands for the North's official name, the Democratic People's Republic of Korea.

The spokesperson's remarks came as concerns have grown that Pyongyang and Moscow have been deepening their cooperation in military, economic and other realms in the absence of a mechanism to thoroughly monitor any activities that might violate UNSC resolutions.

The UN panel's mandate had been extended annually since it was launched in 2009 in line with UNSC Resolution 1874 adopted in response to the North's second nuclear test in May of the same year.

The panel had served as an important institutional platform to oversee sanctions against the North. It had published two reports each year -- an interim report and a final report -- on instances of sanctions violations based on information from UN member states and other open-source materials.