Japan's surplus in spending by overseas travelers declined in July from a year earlier as the number of visitors from South Korea tumbled, a sign the souring bilateral relations are taking a toll on the world's third-largest economy.

The travel account surplus — or the amount spent in Japan by foreign visitors minus that by Japanese traveling overseas — shrank 0.9 percent in July from a year earlier to ¥229.3 billion, according to current account data released Monday by the Finance Ministry.

Japan's decision in July to tighten controls on exports of materials to South Korea, which are used to make semiconductors, has prompted a backlash, with consumers there boycotting Japanese goods and canceling tours.