China’s plan to boost defense spending this year by around 7 percent — the slowest pace since 1991 — will raise concerns and stoke debate in Japan and the U.S. over their own capabilities as Beijing ramps up operations in the waters and airspace of the East and South China seas, experts say.

China’s announcement last week that it will spend 1.04 trillion yuan (about $152 billion) on defense just days after Japan scrambled jets in response to a Chinese military drill that saw fighters, bombers and early-warning aircraft fly through a key strategic entryway into the Western Pacific. It was the latest in a number of Chinese military drills near Japanese territory.

Beijing has vowed to continue to refine its military capabilities through exercises like these that test both the limits — and patience — of Tokyo and Washington.

“The Japan Maritime Self-Defense Force will face an increasingly capable People’s Liberation Army Navy (PLAN), which will raise more concerns and political debates in Japan on whether to enable the JMSDF to strengthen its capabilities,” said Michael Raska, of the Institute of Defense and Strategic Studies at the S. Rajaratnam School of International Studies in Singapore.