WASHINGTON — Travelers who haven’t obtained a REAL ID by this week’s deadline received assurances from the head of Homeland Security that they will be able to fly after additional identity checks. Her comments came Tuesday as people were waiting in long lines outside of government buildings from California to Chicago trying to update their IDs before the long-delayed deadline.

Kristi Noem told a congressional panel that 81% of travelers already have IDs that comply with the REAL ID requirements. She said security checkpoints will also be accepting passports and tribal identification when the deadline hits Wednesday.

Those who still lack an identification that complies with the REAL ID law “may be diverted to a different line, have an extra step,” Noem said.

“But people will be allowed to fly,” she said. “We will make sure it’s as seamless as possible.”

The Transportation Security Administration warned people who don’t have the REAL ID to show up early and be prepared for advanced screening to avoid causing delays.

“I do not have a belief that this will cause people to miss their flights if they take that additional time in,” said Thomas Carter, the TSA’s Federal Security Director in New Jersey. “I think there’s that self-responsibility of the law that they need to know, give themselves that extra time, and if they do that, they shouldn’t have an issue.”

Across the country, government offices extended their hours to help meet the demand. But despite that, some people waited for hours Tuesday to get a REAL ID ahead of the long-delayed deadline.

Renel Leggett, a college student from West Chester, Pennsylvania, spent hours getting her REAL ID and was not happy about it.

“I’ve been out here for three hours to get one ID when I’ve already had one that should have lasted me until about 2029,” Leggett said.

“You have to do it. But it feels like a waste of time,” she said.

REAL ID is a federally compliant state-issued license or identification card that Homeland Security says is a more secure form of identification. It was a recommendation by the 9/11 Commission and signed into law in 2005.

The commission recommended the government set security standards for state-issued driver’s licenses and IDs. It was supposed to be rolled out in 2008. But the implementation has been repeatedly delayed.

Besides needing a REAL ID to fly domestically, people will also need one to access certain federal buildings and facilities.

In recent weeks, Noem has been warning the American public about the upcoming deadline. In a television ad put out by Homeland Security, she warned that these IDs were needed for air travel and for entering public buildings, adding: “These IDs keep our country safe.”