Melania Trump talks to the media after the Republican presidential candidates debate in Miami in March. (ReutersS/Joe Skippe)

This story has been updated.

Melania Trump, the wife of Republican nominee Donald Trump, released a letter from an attorney on Wednesday that includes more details about her immigration to the United States from Slovenia in the 1990s but provides no documentation and leaves some key questions unanswered.

"I am pleased to enclose a letter from my immigration attorney which states that, with 100% certainty, I correctly went through the legal process when arriving in the USA," Melania Trump said in a statement posted on Twitter on Wednesday morning.

The letter was written by Michael J. Wildes, an immigration attorney whose New York-based law firm has done work over the past decade for some of Donald Trump's companies, including Trump Models and the Miss Universe Organization, but has not previously represented Melania Trump.

Wildes writes that news reports that Trump illegally used a tourist visa to work as a model in the United States in 1995 "are not supported by the record, and are therefore completely without merit." He states that Trump was never in the United States in 1995, so it would have been "impossible" for her to have participated in a photo shoot in New York that year, as has been reported. That photo shoot occurred in October 1996 after Trump received a proper work visa, according to Trump.

Wildes lays out this timeline: Trump first entered the United States on Aug. 27, 1996, using a B-1/B-2 visitor visa. On Oct. 18, 1996, Trump received a H-1B visa from the U.S. Embassy in Slovenia to work as a model. Trump received five H1-B visas between October 1996 and 2001, and each visa was good for up to one year. In 2000, Trump self-sponsored herself for a green card based on her "extraordinary ability" as a model. On March 19, 2001, Trump became a lawful permanent resident and a green-card-holder who would be eligible for citizenship in 2006. (The Trumps married in January 2005.)

While the attorney's letter provided new details of Trump's immigration history, the Trump campaign released no documents to support the attorney's timeline. Notably, Wildes provided no details about how Trump proved to the U.S. government that she qualified as a model of "extraordinary ability" when she applied for her green card in 2000.

Melania Trump is a former model, jewelry designer — and potential first lady. Here's your primer on The Donald's third wife. (Julie Percha/The Washington Post)

The United States reserves the "extraordinary ability" designation for those who are "among the small percentage of individuals that have risen to the very top of your field" and that applicants "must demonstrate sustained national or international acclaim." Experts say the green card category is used by people with exceptional and renown talent, including those who win Nobel Prizes and Oscars. In 2000, Trump was a working model best known for her relationship with Donald Trump, but she was not a top international model.

The letter indicates that Trump first came to the United States on a visitor's visa in August 1996 before receiving a work visa in October 1996. Any work she performed for money between those dates might have violated the terms of her visitor's visa. Wildes's letter does not indicate how Trump supported herself between those dates.

Immigration attorney Bruce Morrison, who wrote the "extraordinary ability" provision of federal law when he was a Democratic congressman from Connecticut, said it was known as the "Einstein category."

"It wasn’t always good enough be a player in the starting lineup of major league baseball, you had to be the most valuable player. The expectation was that you had to be truly extraordinary in your field," Morrison said, adding: "If someone came to me with her ability, I would be dubious that she would get it."

Morrison, who supports Democratic nominee Hillary Clinton, said the refusal to provide documentation on his wife's immigration status was part of a pattern for Trump, who has also declined to release his tax records, charitable giving details and other personal information. "These are the people who harassed the president for this birth certificate," he said.

The reference by Wildes to the disputed date of a photo shoot stems from nude photographs of Melania Trump published in July by the New York Post, which many media outlets reported had been taken in 1995 in New York City. Those reports led immigration activists to ask how she could have been working legally for a magazine in 1995 if she got her work visa in 1996.

Marc Dolisi, former editor of the now defunct men’s magazine, Max, told the Washington Post in August that the photos were published in the magazine's February 1996 edition. He said it appeared on newsstands in the middle of January 1996 and therefore had been shot sometime in late 1995.

But in recent days when contacted again, Dolisi said he made a mistake and that the photos were published in the February 1997 edition. The Post has not been able to locate a copy of the magazine.

Rosalind S. Helderman contributed to this report.