Haniyeh welcomed the new cabinet as "a government of one people and one political system."
"We're leaving the government, but not the nation. We're leaving the ministries but not the question of the nation," Haniyeh said in a televised speech.
Hamas and Fatah swore in a "unity" government earlier Monday, despite last-minute tensions which almost prevented the Palestinian Arab reconciliation. The joint government elected Palestinian Authority (PA) official Rami Hamdallah as Prime Minister.
Former PA Chairman Mahmoud Abbas has insisted that a 'unity' government would be based on what he called"the four Palestinian principles": recognizing Israel, recognizing the terms of international agreements, and the explicit rejection of violence and terrorism.
Haniyeh's step down, meanwhile, is a dramatic about-face, after Hamas was adamant over its full control of a "unity" government, expressing over and over again that it would remain in control of both Gaza and the PA after elections and insisting that Haniyeh would rule the government.
More recently, Hamas announced that any "unity" government would be unequivocally subject to their approval before being established.
The group’s charter calls for the destruction of Israel, and at least one top official has ruled out the possibility that Hamas will recognize “the Zionist entity,” even after the unity pact with Fatah.