Protectionism is creating a perception that top talent isn't welcome in Silicon Valley, according to one venture capitalist.

Lu Zhang, founder and managing partner of Palo Alto, California-based venture capital firm Fusion Fund, told CNBC Tuesday, the trade war between the U.S. and China is fostering an "anti-immigrant, anti-international" image for Silicon Valley. This perception could threaten the region's attractiveness to tech entrepreneurs, she said.

"For many years, the reason Silicon Valley has been the hub for innovation is because it's such a diverse community," she told CNBC's Geoff Cutmore at the Boao Forum and Ambrosetti Meeting in Rome.

Tech has been caught in the middle of the trade war between the U.S. and China, despite a 90-day cease-fire announced last weekend that prevented additional tariffs on goods between the two countries. Zhang said protectionist measures from the U.S. could discourage immigrants to set up their companies in Silicon Valley.

More than half of U.S. tech unicorns - companies valued at more than $1 billion - were founded by immigrants, she added.

"We do want to still be able to promote the culture of Silicon Valley," she said.