Transcript for UK threat level raised to critical from severe, prime minister says

This morning I said that the joint terrorism analysis Santa. The independent organization. Responsible for setting the thrash metal on the basis of intelligence a favorable. Was keeping the threat level under constant refuse. It is now concluded. On the basis of today's investigations. But the threat level should be increased. For the time being. From severe to critical. This means that their assessment is not ending it's an attack remains high and likely. But there's a further attack may be imminent. The change in the threat level. Means that there will be additional resources and support made available to the police as they work to keep missile saying. As a result of the police have lost for authorized station from the secretary of state for defense. To deploy a number of armed military personnel in support of them armed offices. This request is pontiff well established plan known as operation tempura. In which both the armed forces and the peace offices involved. Well trained and welcome pat to work in this kind of environment. The secretary of state for defense has approved this request. And operation tempura is now in force. This means that armed peace officers responsible for due to such as guarding key signs. We'll be replaced by members of the armed forces. Which will allow the police to significantly increase the number of armed offices on patrol in key locations. You might also see military personnel deployed at session events such as concerts and sports action news helping the peace to keep the public safe.

This transcript has been automatically generated and may not be 100% accurate.