In February, Japan reported its biggest single-month trade deficit in eight years. High energy prices boosted imports and manufacturers struggled with global supply constraints, leading to a drop in car deliveries.

The growing trade deficit highlights the world's third-largest economy's vulnerability to soaring commodity costs and slowing demand from giant neighbour China as the economy there struggles to maintain momentum.

Imports soared 39.6 % year-on-year in January to a record high in yen terms, reaching 8.5231 trillion yen ($73.81 billion), Finance Ministry data showed on Thursday. That was above the median market forecast of 37.1%.

That greatly outstripped a 9.6% rise in exports in the year to January, bringing the trade balance to a deficit of 2.1911 trillion yen, its biggest in a single month since January 2014.

The deficit was much bigger than the median estimate for a 1.607 trillion yen shortfall.

"Exports tend to go down in January due to seasonal factors as factory operation rates are usually low due to New Year holidays," said Takumi Tsunoda, senior economist at Shinkin Central Bank Research Institute.

"So it's easy for the trade balance to go in the red in the month, but the deficit was still large, even when taking that into account," he added.

A big factor in the deficit was a decline in car exports, said Tsunoda, which swung into contraction from an expansion in the previous month.

Manufacturers, including Toyota Motor Corp and Suzuki Motor Corp, were forced to temporarily close some plants after facing supply chain disruptions and pressure due to a record surge in COVID-19 infections at home.

Imports were boosted by a sharp increase in shipments of oil, coal and liquefied natural gas.

By region, exports to China, Japan's largest trading partner, dropped by 5.4% in the 12 months to January, recording the first decline in 19 months, while imports jumped 23.7%, posting the biggest increase in four months.

This was probably partly due to slower exports and advance demand ahead of the week-long Chinese Lunar New Year, which began on the last day of January.

A bigger cause of worry was the slowing momentum of China's massive economy, which is facing weakening consumption and a property downturn, some analysts said.

"China's economic slowdown could weaken exports going forward," said Ryosuke Katagi, market economist at Mizuho Securities.

US-bound shipments, another key market for Japanese goods, grew 11.5% in January, as stronger machinery shipments outweighed a fall in car exports.

Separate government data showed core machinery orders, which serve as a leading indicator of capital spending in the coming six to nine months, were up 3.6% in December from the prior month, better than an expected 1.8% fall.

Manufacturers expected core orders to decline 1.1% in January-March, after a 6.5% gain in the previous quarter.

Japan's economy grew slightly less than expected in the final quarter of 2021 as falling coronavirus cases helped prop up consumption, government data showed on Tuesday, though a record surge in Omicron variant cases and the high raw material prices are clouding the outlook.