US First Lady Melania Trumps parents became American citizens in a naturalisation ceremony here, completing a year-long immigration process even as President Donald Trump called for new laws to bar Americans from sponsoring parents and other relatives.

Michael Wildes, an attorney for Viktor and Amalija Knavs, who had been living in the country as legal permanent residents after leaving their native Slovenia, confirmed that his clients took the oath of citizenship at the ceremony on Thursday, reports The Washington Post. "Citizenship was just awarded," Wildes said. "They have prevailed in a wonderful journey, as millions have."