Little has changed in the two years since Congress prodded airlines to seat children 13 and younger next to an adult family member at no extra cost.

The reason: The Trump administration has declined to draft new rules detailing how airlines should apply the new law. That means that kids, in some cases, are still being separated from their parents while other families are paying more – in advance – to guarantee seats together.

Consumer advocates have lobbied Transportation Secretary Elaine Chao to start writing regulations to no avail. Instead, the department added a page to its website with tips for traveling families and links to information on airline sites.

That has not satisfied the critics.

“Your inaction makes DOT a witting accomplice to airlines who hold kids hostage and separate them from their families,” Charlie Leocha of Travelers United said in a recent letter to Chao. “The airlines force parents to pay as much as $200 and more per person to protect their toddlers, young children and pre-teens from sitting next to a stranger.”

The airline industry opposed the family-seating requirement and other provisions that Congress included in a 2016 bill governing operations of the Federal Aviation Administration. Industry officials called the provisions an attempt to re-regulate airline prices and services.

A spokeswoman for trade group Airlines for America says decisions about customer service are best left to airline employees.

“Airlines have always worked to accommodate customers who are traveling together, especially those traveling with children, and will continue to do so,” said the industry group spokeswoman, Sarah Soulier.

Airlines say they have deployed new tools to seat families together.

Ross Feinstein, a spokesman for American Airlines, said the carrier has an automated booking system that accommodates families “the vast majority of the time” at no extra cost. When it can’t, he said, gate agents are often able to help families by moving them into any of about 12 seats that are set aside and not assigned until shortly before takeoff.

In cases of last-minute bookings, there might not be four or five seats together so families could be split up, but usually each young child can be seated next to a parent or other family member, he said.

Likewise, Delta Air Lines spokeswoman Lisa Hanna said the airline “does everything possible to work with families so they can sit together.”

Both airlines acknowledge there can be some rare occasions when families are still separated.

John Wellner, a social-studies teacher, said Delta initially refused to seat his 5-year-old and 9-year-old next to him and his wife on a flight this month from Minneapolis to Lima, Peru, unless they paid an extra $200. The situation was resolved, with no extra charges, after Wellner contacted Delta on Twitter.

“I was stunned to learn that a child as young as 5 years old was not required to sit with their parents,” Wellner said. “One bad traveler next to a young kid and I am sure a pretty big lawsuit would be headed their way.”

The problem dates back more than six years. That’s when airlines started to increase the number of coach seats requiring an extra fee or elite status to book in advance. Some of them had extra legroom, but many of those seats were just closer to the front of the plane.

Fliers were either separated from their loved ones or forced to pay $25 extra or more, per seat, each way — including middle seats.

In the July 2016 FAA measure, Congress gave the transportation secretary one year to review airline seating policies and, “if appropriate,” to require all carriers to create a way that children under 14 would be seated next to a family member 14 or older at no extra cost.

Congress left wiggle room, however. It said airlines only had to comply “to the maximum extent practicable.” Lawmakers decided that the requirement would not apply if it meant upgrading a passenger to a better cabin or a better seat with more legroom if the airline normally charged a fee for that upgrade.

Consumer advocates and some travel experts say airlines fail to even offer options when buying a ticket online or on mobile apps to indicate that a passenger is 13 or younger — many sites only ask if a passenger is much younger than that. They accuse the airlines of pressuring parents to pay an extra $25 to $75 per seat assignment to be sure they will be together.

Summer Hull, who writes a family-travel blog called Mommy Points, said she paid $60 extra for upgraded seats on Spirit Airlines for her 3-year-old and 8-year-old on a recent trip to Disney World.

“The airlines are super-clear — they are not guaranteeing you will sit next to your kids. It’s very stressful,” Hull said. The extra $60, she added, “was worth the peace of mind.”

The advent of so-called basic economy seats — which generally don’t allow customers to pick seats until shortly before the flight — has made matters worse, according to Hull, further scaring families into paying more for a ticket that comes with a seat assignment.

Travel experts offer some advice for families:

—Book early to ensure the best selection of seats.

—Don’t buy basic-economy fares, which don’t come with any advance seat assignments, even though they may be cheaper.

—Check the seat-availability chart and pick seats before clicking on “pay.”

— If you must pay fees to find adjacent seats, ask the airline to waive them — you might get a quicker response by contacting the airline on social media.

—If you don’t have assigned seats, or during booking got seats that aren’t next to each other, arrive at the gate early and ask the gate agent for help.

—As a last resort, appeal to the kindness of fellow travelers and ask other passengers if they will trade seats.

Some airlines, like American, set aside a higher percentage of seats for customers willing to pay for more legroom or other amenities. That reduces the number of seats that may be available to families looking for the lowest price.

Unlike other airlines, Southwest does not assign seats. The airline lets adults traveling with a child under seven to board after the first 60 passengers, when there are more open seats, but there is no special provision for slightly older children.

(AP)