TEL AVIV—Hamas released two U.S. citizens taken hostage in the Gaza Strip, amid rising pressure on Israel to put off a planned invasion on the enclave to allow time for diplomacy.

The release was the first time Hamas, the Islamist group that controls the enclave, set free any of the roughly 200 hostages taken by militants during a raid on Oct. 7 that killed more than 1,400 Israelis. Citizens of 41 countries were killed and went missing during the attack, an unprecedented cross-border incursion by militants from Gaza.