(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.

Viktor and Amalija Knavs, the parents of first lady Melania Trump, were granted citizenship Thursday, their immigration attorney , Michael Wildes, announced.

"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.

Read More