The parents of first lady Melania Trump became naturalized U.S. citizens on Thursday, taking the oath in a private ceremony in New York, according to their attorney. 
 
 Viktor and Amalija Knavs are originally from Slovenia but have lived in the United States for over a decade, during which time they gained permanent legal residency, said Michael Wildes, the couple's immigration lawyer. 
 
 Wildes told reporters the couple "have travailed a wonderful journey like millions have, in getting citizenship and waiting the requisite period of time." 
 
 He said that despite having the president of the United States for a son-in-law, the Knavses followed a process to gain their citizenship that "was no different than anybody else's." 
 
 The White House declined to comment on the Knavses' newly acquired citizenship status, saying they were "not part of the administration and deserve privacy." 
 
 After living between Trump Tower and Mar-a-Lago for several years, Viktor and Amalija Knavs reportedly moved to the Washington suburbs following Trump's inauguration,and are frequently spotted traveling with the first lady and the Trumps' son, Barron Trump. 
 
 The question of how the Knavses originally gained their green cards has become a controversial one since Trump won the presidency on an anti-immigration platform. Trump has frequently railed against the family visa system, or so-called chain migration, which permits U.S. citizens to sponsor their family members for visas. 
 
 Even so, experts say chain migration is the most likely way the Knavses gained their permanent residency in the United States. ||||| (CNN) President Donald Trump's in-laws are officially United States citizens, obtaining their citizenship through the sponsorship of their adult daughter, one of the very categories of family visas that the administration has sought to end. 
 
 "It went well and they are very grateful and appreciative of this wonderful day for their family," he said in a statement to CNN. 
 
 The first lady's office declined to comment. 
 
 Viktor and Amalija Knavs, who are from Slovenia, had been living in the United States with green cards and have been frequently spotted in Washington since their son-in-law assumed the presidency. 
 
 A source with direct knowledge of Melania Trump's parents and their immigration status told CNN that Melania Trump sponsored her parents for their green cards, a status that allowed them to live and work in the US indefinitely and paved the way for citizenship. That type of family visa is exactly one of the categories that Trump and his allies have tried to repeal, saying they are harmful to the US. 
 
 Wildes wouldn't comment on how the Knavs received their green cards or citizenship Thursday, but criticized the Trump administration's immigration policies to CNN. 
 
 "I believe strongly in the principles of family reunification, which is a bedrock of immigration policy and law and has brought millions of people happily to our shores," Wildes said. 
 
 Pressed on the fact that the President has harshly criticized family-based migration and regularly refers to it as "chain migration," Wildes responded: "I can't comment on the President's politics when it comes to my clients but I have stood up against the President's immigration policies personally." 
 
 There are only a handful of ways that immigrants to the US can obtain green cards, and the largest share of them each year are given out based on familial connections. A smaller number go to immigrants based on their employment, and other categories include refugees and other special cases. Advocates for restricting legal immigration have pointed to the imbalance in favor of family connections as evidence of the need for reform, calling for a "merit-based" system that would choose immigrants based on need in the US. 
 
 The US allows a number of ways for US citizens and legal permanent residents to sponsor family members to come to the US permanently, including categories for parents, adult siblings and adult children, married and unmarried. 
 
 Trump and his congressional allies have fought to slash that dramatically, limiting sponsorship to spouses and minor children, including dropping the threshold for minor children from 21 to 18. Experts estimate that could cut overall immigration to the US by 40% to 50%, if those green cards are not reallocated to another category. Trump has advocated a "merit-based" system, but has not proposed any method of admitting immigrants to the US to replace those categories. 
 
 Viktor and Amalija Knavs, 73 and 71 years old, respectively, are retired, and they maintain regular contact with the Trump family, often traveling with the first family on trips to Mar-a-Lago and Bedminster, New Jersey.
– The US gained two new citizens of note on Thursday: Viktor and Amalija Knavs, parents of first lady Melania Trump. The couple are natives of Slovenia, where they raised Melania, but have been in the US for more than a decade, says their immigration lawyer, per CNBC. Their path to citizenship "was no different than anybody else's," adds Michael Wildes. The couple reportedly live in the DC suburbs and are frequently seen out with their daughter and grandson, Barron. The couple's exact path to citizenship isn't clear, but one likely possibility is that their daughter's citizenship helped them get green cards first, reports CNBC. As CNN notes, critics have pointed out that President Trump wants to end that type of family-based migration.