BMW sales in China, the carmaker’s biggest national market, dropped for the first time in over two years in May after buyers delayed purchases, hoping for better deals following a cut in import duties.

Deliveries of BMW-brand and Mini city cars in China fell 10 percent in May compared to a year ago, BMW AG said Tuesday in a statement. This compares to sales gains at rivals Mercedes-Benz and Audi. BMW also said low availability of the popular X3 sport utility vehicle in China dragged on its result for the month which burdened global sales to decline 2.1 percent.

“The upcoming changes in import tariffs in China have led to some short-term uncertainty about general pricing,” BMW said in the statement.

The German manufacturer is in the midst of ramping up production of the X3 in China after previously importing the car from its factory in Spartanburg, South Carolina. It’ll be available “in full volume” by the second half of the year. Through May, sales rose 2.5 percent to 248,870 autos.

BMW has vowed to regain the luxury carmaking sales crown from Mercedes parent Daimler AG by the end of the decade. China will play a key role as demand for high-end vehicles continues to outpace sales in other major countries. The world’s biggest car market has cut import duties on passenger cars to 15 percent from 25 percent starting June 1, with carmakers like Ford Motor Co. and Tesla Inc. already lowering prices.