Gasoline prices at the pump in Japan have risen for the seventh straight week, hitting their highest level in about 13 years. The government's attempt to stem the rise is being undermined by the Ukraine crisis, which is pushing crude-oil prices higher.

The Oil Information Center says the average retail price of a liter of regular gasoline nationwide was 172 yen, or about one dollar and 50 cents, as of Monday. That was up 0.35 percent from the week before.

The industry ministry has been taking the unusual move of paying a subsidy to oil wholesalers in an attempt to keep a lid on prices.

Officials say the measure has brought down the retail price by 5 yen, or 4 cents, per liter. But the subsidy has already reached its ceiling.

Tensions in Ukraine have driven crude futures even higher, as traders worry about supplies from Russia, which is a major producer.

The benchmark crude oil prices in New York hit their highest level in seven and a half years.