For further information regarding the definition of critical infrastructure, see here.
It is important to note that senior executives and managers intending to enter the U.S. for the purpose of observing operations, holding regular meetings with U.S. clients, and for routine operational travel will no longer be considered eligible for a National Interest Exception.
National Interest Exception Qualifications
Nonimmigrant visa holders with valid visas are also required to verify that they qualify for a national interest exception (NIE) before they are permitted to travel to the U.S.
A request for a national interest waiver should be emailed to the U.S. consulate where the visa was granted.