A U.N. panel has praised the agreement reached between Japan and South Korea last year to resolve the issue of Korean "comfort women" who were forced to work in wartime brothels for the Japanese military.

The U.N. Human Rights Committee said Monday after a meeting in Geneva that Tokyo "had taken significant steps, including a public apology, recognizing significant responsibility and payment for the women victims."

Monday's meeting was in part intended to review the progress made after the panel put forward recommendations in July 2014 on what Tokyo should do to settle the thorny issue.

While welcoming the government's apology and acknowledgement of its legal responsibility, the panel said Tokyo's efforts to investigate the human rights violations involved and prosecute perpetrators have been insufficient.

In the landmark deal struck on Dec. 28, Japan and South Korea agreed to resolve the comfort women issue "finally and irreversibly."

Under the agreement, the Japanese government admitted its responsibilities over the issue and the involvement of the Japanese military.

It also pledged to contribute ¥1 billion ($9 million) from the state budget to a fund Seoul is to set up for the women.

But the deal came under fire from some U.N. officials, as well as some survivors and their supporters, who have felt Japan's latest apology is inadequate.

Earlier this month, U.N. High Commissioner for Human Rights Zeid Ra'ad Al Hussein urged Tokyo and Seoul to heed the voices of former comfort women on the bilateral accord.

"Its terms have been questioned by various U.N. human rights mechanisms, and most importantly by the survivors themselves," he said at the time.

"It is fundamentally important that the relevant authorities reach out to these courageous and dignified women. Ultimately only they can judge whether they have received genuine redress," the official said.