You create a pair of grasping hands made from invisible force. Make a ranged spell attack against a creature which has a neck and breathes through it and you can see within range. On a hit, the creature has the Restrained condition. While it has this condition, it can't breathe.

A creature can hold its breath for a number of rounds equal to 1 plus its Constitution modifier (minimum of 30 seconds) before suffocation begins. When a creature runs out of breath, it gains 1 Exhaustion level at the end of each of its turns. When a creature can breathe again, it removes all levels of Exhaustion it gained from suffocating.

A creature Restrained by the hands can take an action to make a Strength (Athletics) check against your spell save DC. If it succeeds, it is no longer Restrained and the spell ends.

AN: Original spell had only 1 minute duration and the wording wasn't totally clear. As written it had this problem: If I'm reading this right. Each creature has 5 turns where its only restrained by the hands and then another 5 turns where it begins to suffocate (if it failed all the saves). It it would mean the sufforation would never kill any creature, because you need 6 levels of exhaustion to die.
AN2: Also another version of WoW Strangulate.