(IDEX Online) - The United States has blacklisted Myanmar's state-owned gem company following the removal of state counsellor Aung San Suu Kyi as leader in a military coup in February.Myanma Gems Enterprise, part of the country's ministry of mines, is said to be responsible for all sales of the country's ruby, jade and other gems.The US Treasury Department has banned it from any trade with the United States. The move follows two earlier rounds of sanction on gemstone exporters in Myanmar, in a bid to deprive the new regime of revenue from foreign sales.The country produces 90 per cent of the world's high-end rubies, many of its most expensive sapphires, and it supplies China with much of its jade.More than 600 demonstrators against the new regime have reportedly been killed since the military seized power in Myanmar.US Secretary of State Antony Blinken said in a statement that the United States would "keep increasing pressure on the regime's revenue streams until it ceases its violence, releases all those unjustly detained, lifts martial law and the nationwide state of emergency, removes telecommunications restrictions, and restores Burma to the path of democracy."