Reacting to the crash of a Russian plane over Egypt that killed all 224 people aboard, the U.S. Department of Homeland Security announced Friday additional security measures for commercial flights bound for the United States at a number of airports across the Middle East, NBC News reported. The locations will include airports in Cairo, Kuwait City and Amman, Jordan, NBC reported.

Russian President Vladimir Putin also suspended all flights to and from Egypt, and Britain suspended all flights from Sharm el-Sheikh, Egypt -- the doomed flight's origin point -- earlier this week.

“While there are no direct commercial air flights from Sharm el-Sheikh, Egypt, to the United States, these enhancements are designed to provide an additional layer of security for the traveling public, and will be undertaken in consultation with relevant foreign governments and relevant passenger and cargo airlines,” Secretary of Homeland Security Jeh Johnson said in a statement, according to a news release. 

The new measures include expanded screening of any items that go onto planes, airport assessments in conjunction with international partners, and offers of security assistance to those airports.   

The British had already concluded that the crash over the Sinai Peninsula last Saturday was most likely caused by a bomb, and U.S. President Barack Obama said he takes the possibility “very seriously,” the New York Times reported. The Sinai branch of the Islamic State group claimed responsibility, and threatened more terrorism against Russia in retaliation for the country's intervention in Syria.

While the ISIS threats were at first dismissed, mounting evidence has since suggested otherwise to many countries. Egypt, however, continues to deny the possibility that the crash was the result of a terrorist attack. Information recently recovered from the plane's flight data recorder, however, seems to indicate that “everything was normal during the flight, absolutely normal, and suddenly there was nothing,” according to a source involved in the investigation in Paris, Agence France-Presse reported.