Soldiers from the 2nd Battalion, The Princess of Wales's Royal Regiment joined Council Leader, Councillor Liam Smith to fly the Armed Forces flag from the roof of the Civic Centre, Dagenham.
The event is part of the activities taking place across the country to mark Armed Forces Day.
Councillor Liam Smith, said: "In this, the fourth year celebrating Armed Forces Day, Barking and Dagenham is demonstrating its support for the men and women of our armed forces.
"This is a chance for us all to say a heartfelt thank you to our troops, to let them know they are always in our thoughts and that we truly value their contributions and sacrifices. It is also an opportunity to remember those who have fallen in service to our country.
"Sharing this special honour with the men and women of our armed forces is testament to the affection, gratitude and the pride that the Council and the people of the borough feel for them and their families."