The figure is down 12.1 percent from $1,442 a year ago and marks the fourth quarterly decrease in a row.

Average spending hovered around $1,200 in the mid-2000s but rose to $1,298 in 2010 and subsequently grew steadily every year to peak at $1,713 in 2015.

However, diplomatic tension with China over Seoul's deployment of a key US defense system -- Terminal High Altitude Area Defense -- slashed the tourist spending figure to $1,625 in 2016 as Chinese tourists shied away from South Korea. Since that year, the number has steadily been on a downturn, taking it back to its 2009 level this year.

The data also showed that Chinese tourists were the national group who spent the most in South Korea in the first quarter, with an average of $1,735 in expenditure, followed by Taiwanese with $1,131 and Americans with $1,103.

The average duration of stay by foreign tourists came to 6.9 days in the first quarter, down slightly from seven days a year earlier.

The level of satisfaction shown by foreign tourists who visited Korea came to 93.9 percent, up slightly from 93.7 percent a year ago. (Yonhap)