WASHINGTON (Reuters) - More than 30 U.S. business leaders urged Congress on Tuesday to undo visa restrictions that make it harder for citizens of some countries to visit, saying they were discriminatory and made U.S. companies less competitive.

A law passed after last year’s Paris attacks by Islamic State requires citizens of 38 countries to obtain a visa to visit the United States if they are dual Iranian, Iraqi, Sudanese or Syrian nationals, or have visited those countries since March 2011.

Previously, citizens of countries in the Visa Waiver Program could travel to the United States for up to 90 days without a visa.

Twitter Inc Chief Executive Officer Jack Dorsey, Pixar President Ed Catmull, former eBay Inc President Jeff Skoll, billionaire Mark Cuban and about 30 other mostly technology executives and investors signed on to a letter delivered to legislators on Tuesday that said the changes amounted to discrimination based on national heritage.

“We protest this just as vigorously as if Congress had mandated special travel papers for citizens based on their faith or the color of their skin,” the letter said. “In the balancing act between fighting terrorism and upholding American liberties, these provisions go too far.”

The changes would result in “bureaucratic delays” that would make U.S. companies less competitive with their global counterparts, the letter said.

The signers included prominent political donors, including PayPal Holdings Inc and Uber investor Scott Banister, who has supported libertarian causes.

Several Iranian-American executives and investors also signed, including Twitter Chairman Omid Kordestani and former Chief Operating Officer Ali Rowghani, and Dropbox co-founder Arash Ferdowsi.

Ali Partovi, an Iranian-American investor and start-up advisor who organized the letter, said those who signed on were particularly offended by discrimination against the Iranian-American community, an influential and prosperous population in the tech world.

“Silicon Valley’s top ranks and bottom ranks and middle ranks are filled with Iranians,” Partovi said. “It’s very awkward and very offensive to have a discriminatory law like this affecting a group that so many people work closely with.”

The Visa Waiver Program came under scrutiny in Congress after the Paris attacks because some of the militants behind the attacks were European nationals theoretically eligible for U.S. visa waivers, who had become radicalized after visiting Syria.

Tuesday’s letter expressed support for the Equal Protection in Travel Act, a bill introduced last month that would reverse some of the limitations.