TOKYO, June 8 -- The Japanese government on Wednesday said that it was liaising with the United Statesand South Koreaover concerns that the Democratic People's Republic of Korea (DPRK) may have resumed its production of plutonium for possible use in nuclear warheads.

Japan's top government spokesperson, Chief Cabinet Secretary Yoshihide Suga, told a press conference that Japan was "gravely concerned" at the reports of plutonium production and views the potential development of such with consternation.

Suga stated that the Japanese government is "working in cooperation with the United States and South Korea on information gathering and surveillance."

Suga's remarks follow a report carried by Reuters as quoting a senior U.S. State department official as saying that a processing plant in Pyongyang is operational again, which suggested the renewed production of possible weapons-grade plutonium by the DPRK.

Underscoring the reports, the International Atomic Energy Agency (IAEA) has also said it has noticed increased activity at the plant in question.

On Wednesday, Japanese Prime Minister Shinzo Abe, for his part, paid a visit to the nation's Cabinet Satellite Intelligence Center, which is located in the capital, and is the operational headquarters of Japan's network of intelligence satellites.

The visit by Abe, according to his top spokesperson, was to motivate the workers there and oversee their duties and the facility in general, in a move that could also be interpreted as a sign that Tokyo is gearing up to deal with more ballistic missile launches from the DPRK that have been occurring since the start of this year, or at least ramp up its own surveillance.

Japan's Defense Minister Gen Nakatani, however, recently canceled the deployment of the ministry's Patriot Advanced Capability-3 (PAC-3) surface-to-air guided missile interceptors, saying there was no immediate threat from potential ballistic missile launches from the DPRK.