A spokesman for China's Foreign Ministry said on Tuesday evening that Japan's new pledge to return sensitive nuclear material reportedly given to it by the United States is the first step in the correct direction.

Hong Lei made the remarks when commenting on the Japan-U.S. nuclear deal announced on Monday at the 2014 Nuclear Security Summit in the Netherlands.

"China welcomes the deal," Hong said, adding that China appreciates and supports U.S. efforts in getting back its overseas nuclear material.

"We are also glad to see the effects brought about by the calls of the international community," he said.

Hong called for Japan to make continuous concrete steps in this regard, saying China hopes for an early settlement of the supply-demand imbalance of nuclear material in Japan.

"Japan still stockpiles other sensitive nuclear materials, which far exceed its actual normal needs," he said.

Under the deal, Japan and the United States will remove and dispose of all highly enriched uranium (HEU) and separated plutonium stored at the Japan Atomic Energy Agency (JAEA)'s Fast Critical Assembly,

The material, once securely transported to the United States, will be sent to a secure facility and fully converted into less sensitive forms.

The United States gave 331 kg of weapons-grade plutonium to Japan during the Cold War, Japan's Kyodo News Agency reported in late January. The United States has been pressing Japan to return the material since the first nuclear security summit in 2010.