A U.S. transportation security agency said Wednesday it plans to issue new cybersecurity requirements for some key aviation systems after several U.S. airport websites earlier this week were hit with apparently coordinated denial-of-service attacks.

The Transportation Security Administration (TSA) said Monday's cyberattacks that were allegedly organized by pro-Russian hackers "did not disrupt airport operations or access to information."

TSA has "updated its aviation security programs to require airport and airline operators designate a cybersecurity coordinator and report cybersecurity incidents, conduct a cybersecurity assessment, and develop remediation measures and incident response plans." TSA added it plans to "soon issue additional performance-based cybersecurity requirements for critical aviation systems," the agency said.