US President Donald Trump's executive order restricting entry of skilled foreign workers into the country, mainly on H-1B and L1 visas, has resulted in an estimated loss of $100 billion to companies and will have lasting negative impacts on firms, according to a prominent American think-tank. The H-1B visa, most sought-after among Indian IT professionals, is a non-immigrant visa that allows US companies to employ foreign workers in speciality occupations that require theoretical or technical expertise. L-1 visa is for internal company transfers.