Japan's trade surplus jumped 35.2 percent in May from a year ago to 384.9 billion yen, marking the first jump in 17 months on brisk auto exports to the United States, the Finance Ministry said Thursday.

Exports rose 18.9 percent to 5.7 trillion yen, while imports climbed 17.9 percent to 5.32 trillion yen, pushed higher by soaring oil prices, the ministry said in a preliminary report.

Japan's total auto exports rose 27.7 percent to 919.4 billion yen, with auto exports to the United States surging 34.7 percent to 392.79 billion yen, it said.

Imports of crude oil jumped 35.2 percent to 864.05 billion yen due to record-high oil prices, averaging $66.40 per barrel in May on a customs-cleared basis, up 29.8 percent from year-ago levels.

Economists predict the rising trend in exports will continue in the coming months, given the steady growth of the world economy. But they said the trade surplus is unlikely to keep growing because imports are also expected to rise due to high oil prices and firm domestic demand.

The report said the trade surplus with the U.S. rose 23.0 percent to 627.5 billion yen, up for the 16th month in a row.

Exports to the United States grew 20.6 percent to 1.3 trillion yen, while imports rose 18.3 percent to 672.5 billion yen.

Japan's trade surplus with other Asian economies increased 25.5 percent to 439.6 billion yen, a turnaround from the 23.3 percent decline in April.

Exports to Asia climbed 15.9 percent to 2.72 trillion yen, while imports rose 14.2 percent to 2.28 trillion yen.

The trade deficit with China, not including Hong Kong, stood at 214.6 billion yen, with exports rising 29.4 percent to 831.5 billion yen and imports up 15.0 percent to 1.05 trillion yen.

The trade surplus with the European Union ballooned 39.9 percent to 243.1 billion yen.