In a huge blow to Indian IT professionals eyeing the US job market, President Donald Trump on Monday signed an executive order preventing federal agencies from contracting or subcontracting foreign workers mainly those on H-1B visa from hiring.The move came over a month after the Trump administration in June 23 suspended the H-1B visas along with other types of foreign work visas until the end of 2020 to protect American workers in a crucial election year. The new restrictions took effect from June 24. The H1B 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.