Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. President Trump: Iran 'Made A Very Big Mistake!' Jeff Seldin WASHINGTON - VOA's Carla Babb, Steve Herman, Katherine Gypson, Ken Bredemeier contributed to this report President Donald Trump has fired a warning shot at Iran via social media, hours after U.S. defense officials confirmed Tehran shot down a U.S. drone over international airspace. "Iran made a very big mistake!" Trump said on Twitter Thursday, as tensions between Washington and Iran continued to escalate following the alleged attacks on two oil tankers in the Strait of Hormuz last week. Iran made a very big mistake! -- Donald J. Trump (@realDonaldTrump) [1]June 20, 2019 Earlier Thursday, Iran's Revolutionary Guard claimed to have shot down a U.S. RQ-4 Global Hawk drone over Iranian airspace. "Borders are our red line," Revolutionary Guard commander Gen. Hossein Salami told a crowd in the western city of Sanandaj, in a televised address. "`Any enemy that violates the borders will be annihilated." But U.S. Central Command, which oversees U.S. military activity in the region, quickly refuted the Iranian claim. "This was an unprovoked attack on a U.S. surveillance asset in international airspace," CENTCOM spokesman Capt. Bill Urban said in a statement, arguing the drone had been operating over the Strait of Hormuz when it was taken down by a surface-to-air missile on Wednesday. References Visible links 1. https://twitter.com/realDonaldTrump/status/1141711064305983488?ref_src=twsrc%5Etfw Hidden links: 2. file://localhost/middle-east/iran-shoots-down-us-drone .