Samsung Electronics on Friday warned of sluggish sales of its artificial intelligence chips in the current quarter due to U.S. export restrictions to China, and as it worked towards launching an improved version of its high-end chips.

The world’s largest maker of memory chips and smartphones posted better-than-expected net profit for the fourth quarter, but its core semiconductor business weakened sequentially.

Samsung Electronics said on Jan. 31 that its semiconductor (DS) division posted revenue of 30.1 trillion won ($20.7 billion) and operating profit of 2.9 trillion won in the fourth quarter of last year.