A group of 60 leaders of some of the country's largest companies sent a message Wednesday to the Trump administration: Recent changes in the nation's immigration policies threaten to "undermine economic growth and American competitiveness."

In a letter to Secretary of Homeland Security Kirstjen Nielsen co-signed by members of the Business Roundtable--an influential trade association of American companies--the executives called out U.S. Citizenship and Immigration Services (USCIS) for causing difficulties for companies that employ H-1B workers. The list of well-known business leaders to sign the letter included Apple's Tim Cook, Salesforce's Marc Benioff, and PepsiCo's Indra Nooyi.

Since 2017, USCIS has issued several changes that have resulted in an increased number of denials or longer processing times for H-1B visas, which are granted to highly skilled foreign workers coveted by tech companies, The New York Times reports. These changes can allow officials to deny an employee's visa renewal petition despite multiple prior approvals and no material change in facts.

Individuals may also face immediate deportation proceedings if their change in status (from visa holder to green card) or visa renewal is denied. This would prohibit workers from willingly returning to their home countries until they go through a deportation hearing.

Overall, the executives said, USCIS has increased the likelihood that law-abiding, long-term H-1B employees will lose their status.

"Inconsistent immigration policies are unfair and discourage talented and highly skilled individuals from pursing career opportunities...at a time when the number of job vacancies are reaching historic highs due to labor shortages," the executives write. "Now is not the time to restrict access to talent."