The defence spending was part of a $912-billion national budget for the fiscal year starting in April 2019, approved by Prime Minister Shinzo Abe's cabinet.

The government decided to set aside 5.26 trillion yen ($47 billion) for defence, the fifth record year in a row, defence ministry officials said.

The defence funding will cover the cost of introducing the US military's Aegis Ashore land-based missile interceptor system, the officials said.

The FY 2019 allocation covers six F-35A stealth jets, and part of it will be spent on Japan's first aircraft carriers since World War II.

The budget is the initial allocation of Japan's new five-year defence plan, announced on Tuesday as the latest in a series of steps under Abe to boost the nation's military.

Under the multi-year programme through March 2024, Japan will upgrade two existing helicopter carriers so that they can launch fighters.

Abe's government argues the efforts are necessary given growing defence challenges in the region, including tensions with North Korea, and particularly "strong concerns" about the expansion of China's military footprint.

But the move is controversial, with critics arguing it shifts Tokyo further away from its commitment to strictly defensive capabilities under Japan's post-WWII pacifist constitution.

Beijing immediately expressed its "strong dissatisfaction and opposition" to the programme unveiled on Tuesday, urging Tokyo "to adhere to a purely defensive policy".

Last year, China unveiled its first domestically built aircraft carrier as it continues to assert claims in the South China Sea. Beijing's first carrier, the Liaoning, is a second-hand Soviet ship built nearly 30 years ago and commissioned in 2012.

Japan's new programme comes after pledges to buy more US military equipment, under pressure from President Donald Trump.

The US leader has repeatedly complained about Washington's huge trade deficit with Tokyo and also urged Abe to expand the country's defensive capacity.

For his part, Abe has campaigned for years to amend Japan's pacifist constitution, arguing that it ties the hands of the country's Self-Defense Forces (SDF) even in protecting the country's allies from attack.

"Japan's growing defence budget is directly aimed to counter China's military threat," said Akira Kato, professor of international politics and regional security at Tokyo's J.F. Oberlin University.

"The budget gain is also part of Japan's efforts to buy more US military equipment so that it can avoid a trade war with Washington," Kato told AFP, adding that Tokyo's defence budget is expected to continue expanding.