TOKYO » Japan sounded the alarm Tuesday (Monday in Hawaii) on rising security threats in Northeast Asia, warning in a government report of a potential military confrontation with China over maritime disputes, as well as a North Korean weapons program that appeared intent on producing longer-range nuclear missiles.

Japan’s annual defense paper, the first since Prime Minister Shinzo Abe took office in December, also raised concerns that budget cuts in the United States and a range of other distractions would hinder Washington’s much-touted “pivot to Asia” — a strategic reorienting of U.S. interests from Europe and the Middle East toward East Asia.

“In its defense strategic guidance, the U.S. presented policies emphasizing a rebalance toward the Asia-Pacific region,” the report drawn up by Japan’s Defense Ministry said. “But how its harsh financial situation will impact efforts to translate these policies into reality attracts attention.”

Abe, a conservative, has been keen to revamp Japan’s military strategy to offset China’s growing military power and the continuing instability on the Korean Peninsula.

In January, he ordered his government to replace the nation’s five-year military spending plan and to review guidelines adopted in 2010 by the left-leaning Democratic Party, which would have shrunk the Japanese military’s ranks. Instead, Abe plans to increase Tokyo’s military spending for the first time in a decade.

Abe has also sought to bolster military cooperation with the United States, including holding joint military training drills with Tokyo’s longtime security ally. But Japan has struggled to hold America’s attention. President Barack Obama skipped a meeting with Abe on the sidelines of the Group of Eight summit in Northern Ireland last month.

Even as Washington has remained distracted by other matters, the report warned, the security situation in Northeast Asia was turning increasingly volatile.

Tokyo is particularly worried by what the report called Chinese intrusions into waters around islands claimed by both countries. Since last year, Japanese and Chinese patrol ships have been engaged in a tense face-off near the Senkaku islands, a set of uninhabited islets in the East ChinaSea that China calls the Diaoyus.

Though there have been no clashes so far, some experts have warned that an incident at sea could inadvertently trigger a wider military confrontation between the two Asian powers. In January, Tokyo accused a Chinese military vessel of aiming radar used to help direct weapons on a Japanese naval vessel near the islands. That came after Japan scrambled fighter jets in response to a Chinese military surveillance plane that had entered what Japan considers its airspace.

China’s “intrusion into Japan’s territorial waters, its violation of Japan’s airspace and even dangerous actions that could cause a contingency situation, which are extremely regrettable,” the report said. “China should accept and stick to the international norms.”

The Japanese government has also been rattled by renewed belligerence from North Korea, which fired off a long-range rocket in December and conducted its third nuclear test in February. Those moves suggest that North Korea is pushing ahead with plans to develop more advanced and longer-range missiles that could ultimately carry nuclear warheads.

“We assess that North Korea’s ballistic-missile development is considered to have entered a new phase,” the report said.

Coupled with its nuclear tests, North Korea’s weapons program “has developed into a more real and imminent problem for the wider international community,” it said.