The type of warfare where an attacker surrounds and traps an enemy inside of a fortified city or a fort until they surrender or die due to lack of supplies, especially food, is a siege.
Explanation:
A siege is a long-standing military blockade of a city (or fortress) with the aim of taking it either by military force or by starving its population and military crew.
The purpose can be to capture buildings, resources, strategic locations or destroy enemies. Usually the siege warfare is a war mode that must be carried out in the case of a last resort, because it often takes a huge price to achieve the goal.
