The exchange rate of Mongolia's national currency, the Tugrik, against the U.S. dollar weakened by 8.4 percent, and against the Chinese yuan weakened by 3.8 percent year-on-year in 2018, official data showed Wednesday.

At the end of 2018, the exchange rate of the U.S. dollar against the Tugrik stood at 2,637.35, while one yuan could buy 383.03 Mongolian Tugriks, according to the National Statistics Office of Mongolia.

The Tugrik's depreciation was directly caused by higher imports that led to an outflow of the foreign currencies, the statistics office said, adding that the value of Mongolia's total imports amounted to 5.9 billion U.S. dollars in 2018, up 35.5 percent from the previous year.

The U.S. dollar and the yuan have been maintaining their strength against the Tugrik so far this year. On Wednesday, Mongolia's central bank set the rate at 2,662.86 Tugriks per dollar and 394.36 Tugriks per yuan.