South Korean citizens' credit card spending in foreign countries jumped to a new high in the second quarter of 1.5 billion U.S. dollars, the Bank of Korea (BOK) said Friday.

According to the central bank, overseas credit card spending by South Koreans in the April-June period rose 31.1 percent from a year earlier. The number of credit card users abroad advanced 39.3percent year-on-year to 2.3 million.

"The rise is attributable to a sharp increase in the number of residents going on overseas trips and the won's gain against the greenback," said a statement by the BOK.

In the second quarter, 3.16 million Koreans went overseas, up 18 percent from the previous year. During the same period, 1.58 million foreigners -- only half of the number of South Korean travelers abroad -- entered the country.

The average exchange rate between South Korean currency won and U.S. dollar climbed to 929.26 in the second quarter from 950.41 a year earlier.

On average, one South Korean put 643 U.S. dollars on credit cards in foreign countries during the three-month period, down 5.9percent from a year earlier, the central bank said.