TAIPEI (Reuters) -The chief executive of Taiwan's top chip design company MediaTek ( MDTTF ) said on Wednesday he was unable to give full-year earnings guidance due to uncertainty about U.S. tariffs, but that he was generally optimistic given strong AI demand.

Tech firms in Taiwan, home to the world's largest contract chipmaker TSMC, face the possibility that U.S. President Donald Trump will put tariffs on imported chips, though earlier this month he paused earlier plans for sweeping import charges on all countries for 90 days.

Asked on a quarterly earnings conference call about the impact on the company, whose partners and clients include artificial intelligence giant Nvidia ( NVDA ), from any future U.S. tariffs, MediaTek's ( MDTTF ) CEO Rick Tsai said they were cautious about the second half.

"The first half is reasonably positive. Because of uncertainty we will not give, as we usually have, a full year outlook this year," he said.

"But what I can say is: at least qualitatively, we are not overly pessimistic. We strive to achieve still a good, positive 2025."

Tsai said he remained upbeat on the AI market.

"For the mid- to long-term, we believe the trend towards ubiquitous AI remains intact and our growth prospects remain solid," he added.

TSMC, in its earnings call earlier in April, gave a bullish outlook for the year on robust demand for AI applications, and did give full year guidance, adding that it had yet to see any change in customer behaviour, despite tariff uncertainty.

MediaTek's ( MDTTF ) shares have fallen 4.6% so far this year, outperforming the broader market's 12% dip. The company's shares closed down 1.5% on Wednesday ahead of its earnings call.