U.S. budget carrier Frontier Airlines said Tuesday it has introduced measures under which at least one parent will automatically be seated with any children within their family group who are under the age of 14, at no additional cost.

This comes after President Joe Biden, earlier this month, harshly criticized U.S. airlines saying they were charging families unfair fees and vowing to implement new consumer protections.

This also prompted United Airlines Holdings Inc. to announce Monday "an improved family seating policy" that will make it easier for children under 12 years to sit next to an adult in their party for free. This includes customers who purchase basic economy tickets. The complete policy change will go into effect in early March.

U.S. airlines face growing calls in Congress to boost consumer protections after a series of disruptions including a holiday meltdown at Southwest Airlines Co. that resulted in the cancellation of more than 16,000 flights.

• United Airlines Introduces New Family Seating Policy