TOKYO >> U.S. and Japanese officials said Thursday they will position a second early-warning radar in Japan within the next year and deploy new long-range surveillance drones to help monitor disputed islands in the East China Sea by next spring, moves that may well raise tensions again with China.

The foreign and defense ministers of the two countries also, for the first time, put a price on what Japan will contribute to the relocation of Marines out of Okinawa to Guam and other locations in the Asia-Pacific region. Japan will pay up to $3.1 billion of the move, which includes development of new facilities in Guam and the Northern Mariana Islands.

The announcements came at the close of high-level meetings between U.S. Secretary of State John Kerry and U.S. Defense Secretary Chuck Hagel with Japanese Foreign Minister Fumio Kishida and Defense Minister Itsunori Onodera. The talks, ahead of President Barack Obama’s visits to Indonesia and Brunei next week, were aimed at modernizing the American-Japanese alliance that both sides maintain is a cornerstone of peace and stability in North Asia.

The new X-band radar system would boost Japan’s ability to track and intercept missiles from across the Sea of Japan and will be set up on the west coast. Officials have said it is aimed at protecting the region against the threat from North Korea, and is not directed at China.

But the drones — two or three that will fly out of a U.S. base — are designed in part to help step up surveillance around the Senkaku islands, a source of heated debate between Japan and China.

More broadly, however, the documents agreed to on Thursday contain no direct mention of the Senkakus, easily one of the most contentious issues affecting security in the Pacific.

The territorial dispute over the remote, uninhabited islands has badly soured China-Japan relations and led to bellicose talk and actions from both sides.

The U.S. has watched warily as tensions between Japan and China have heated up over the Senkakus. China has increased patrols near the Japanese-administered islands that it calls Diaoyu. The cat-and-mouse between their ships and aircraft continues, and Beijing and Tokyo aren’t even close to settling their dispute.

Successive U.S. administrations have held to the position that the two nations must sort out their differences over the Senkakus peacefully, and that remains the case. U.S. officials said the position was so well known that there was no need to address it in the agreements.

A senior U.S. official traveling with Kerry said Washington would continue to make the point that while it takes no side on the question of the islands’ sovereignty, it recognizes Japan’s administration of them and has responsibilities to protect Japanese territory under a mutual defense treaty.

The official said the administration continues to believe that the most effective policy is to continue to make those points publicly and privately while encouraging the two sides to tone down rhetoric and refrain from actions that may be seen by the other as provocative. It is not in U.S. interests, nor those of Japan or China, for the chill between Tokyo and Beijing to be prolonged, the official said.

The islands, also claimed by Taiwan, stir a depth of nationalist passion that belies their size and remoteness. They are located roughly midway between Taiwan and the southern Japanese island of Okinawa, and cover a total area of just 2.3 square miles.  

Over the past year, Japan’s coast guard says there have been more than 200 intrusions by foreign vessels into Japanese-claimed waters near the islands. The closest call came in February, when Japan said a Chinese ship locked its weapons fire-control radar onto a Japanese ship in a hostile act. China denied it.

A senior U.S. administration official said the new radar, which was initially announced by then-Defense Secretary Leon Panetta about a year ago, will provide better coverage in the event of a North Korean attack. There already is one of the X-band radar systems in the northern part of Japan, but the official said the second one, to be located in the Kyoto Prefecture, will fill gaps in coverage.

The official said details about the deployment of the U.S. Global Hawk drones were still being worked out. The plans also included deployment of F-35 jet fighters for the Marines around 2017.

More broadly, the 10-page statement signed by Kerry and Hagel was designed to improve military and diplomatic relations with Japan, while working to reduce America’s troop footprint on the island.

The U.S. force of 50,000, particularly troops in Okinawa, has increased tensions between the two nations, over the military’s land use, crimes committed by service members and disruptions by military flights in the heavily-populated region.

Under plans announced last year, about 9,000 Marines stationed on Okinawa will be moved out. The decision also reflects the Obama administration’s effort to focus greater attention on the Asia-Pacific, and spread troops more widely across the region.

About 5,000 Marines will go to Guam. The total cost of the relocation is about $8.6 billion.

Earlier Thursday Kerry and Hagel visited the secular Chidorigafuchi National Cemetery, where the remains of more than 350,000 unidentified war dead from World War II are laid to rest.

They did not go to the nearby Yasukuni Shrine, a controversial monument that honors 2.5 million Japanese soldiers who died in wars from the late 1800s until 1945, including convicted war criminals.