"As a matter of routine, as a precaution, we review our plans after attacks overseas, and we are doing so at present following the awful incidents in Berlin and Ankara last night," the statement reads.
The Metropolitan Police added that the detailed plans for protecting public events in place "already recognise that the threat level is at 'severe', meaning an attack is highly likely."
On Monday, Russian Ambassador Andrey Karlov was killed by a gunman at an art gallery exhibition opening in Ankara. Three other people were also injured in the attack. The Russian Foreign Ministry called the incident an act of terrorism.
The truck, which rammed into a crowd of people at a Christmas market in Berlin late on Monday, killed at least 12 and injured almost 50 people. The police confirmed that the truck-ramming was intentional.
