The Trump administration is tightening visa rules in a bid to stop foreign women from traveling to the U.S. with the sole purpose of giving birth so that their children will gain American citizenship, a phenomenon that has drawn the ire of conservative groups. Starting Friday, U.S. consular officers overseas must deny visas to women coming to the country for that reason, the State Department said. A department official, briefing reporters on condition of anonymity, said thousands of such births happen every year. “The birth tourism industry threatens to overburden valuable hospital resources and is rife with criminal activity, as reflected in federal prosecutions,” White House spokeswoman Stephanie Grisham said in a statement. “Closing this glaring immigration loophole will combat these endemic abuses and ultimately protect the United States from the national security risks created by this practice.” The number of such births is a tiny fraction of the roughly 4 million babies born in the U.S. every year but has become a target of criticism by conservative groups, which argue that such “anchor babies” often are used to help other family members immigrate later and take advantage of U.S. services. President Donald Trump has decried birthright citizenship, which is guaranteed by the U.S. Constitution, and said in October he may try to overturn it. The move is the latest in a range of actions taken by the Trump administration to restrict immigrant inflows and could be targeted toward bolstering his political support before the November elections. He’s also planning to add to a list of countries that face strict visa restrictions and has diverted billions of dollars in funding to build a border wall with Mexico. Yet the new rule still has several loopholes. For example, consular officers have been told not to ask all female applicants if they’re pregnant, and pregnant women will still be admitted if they’re coming to the U.S. primarily for other medical treatment or to visit a sick relative. Many U.S. visas are issued for 10 years, so it isn’t clear what measures U.S. officials could even take if a pregnant woman with a previously issued visa is traveling to the U.S. to give birth. The State Department official also declined to explain how officers should determine whether a woman will give birth during her stay unless she says so on her application form, and wouldn’t say if visual cues -- such as the applicant appearing to be pregnant -- could serve as grounds to deny a visa. The State Department’s new rule targets so-called B non-immigrant visas, which cover temporary travel to the U.S. for business or pleasure. It also seeks to tighten rules on “medical tourism” by demanding that applicants show they’ll be able to pay for treatment. Hong Kong Express Airways has already been caught up in concerns over birth tourism. The airline apologized this month after a 25-year-old Japanese citizen said she was forced by the airline to take a pregnancy test in November to travel from Hong Kong to Saipan, a U.S. territory, according to NBC News. The airline said it required the test after Saipan authorities had raised concerns. The State Department official speaking to reporters on Thursday said the department wouldn’t require pregnancy tests for applicants. Subscribe to our YouTube channel: https://bit.ly/2TwO8Gm QUICKTAKE ON SOCIAL: Follow QuickTake on Twitter: twitter.com/quicktake Like QuickTake on Facebook: facebook.com/quicktake Follow QuickTake on Instagram: instagram.com/quicktake Subscribe to our newsletter: https://bit.ly/2FJ0oQZ Email us at [email protected] QuickTake by Bloomberg is a global news network delivering up-to-the-minute analysis on the biggest news, trends and ideas for a new generation of leaders.