Mr Merkley, a Democrat representing Oregon, said in a statement released on Monday that he came to his decision after “many Americans, including thousands of Oregonians, have raised their voices to say more must be done to stop the carnage.”
“I am calling for a ceasefire—a cessation of hostilities by both sides. To endure, the ceasefire and the following negotiations must accomplish other essential objectives, including the release of all hostages and a massive influx of humanitarian aid,” he said.
Senator Merkley joins Dick Durbin, a Democrat representing Illinois, to become only the second lawmaker in the US Senate to call for a ceasefire, joining some 40 members of the House of Representatives.
Mr Merkley wrote that the ceasefire requires “an immediate cessation of military hostilities by both sides. But the ceasefire and the negotiations that follow must accomplish a number of objectives or it will not endure. “
“Hamas must release all the hostages without conditions and lay down their arms. And Hamas, which continues to defend the savage slaughter of Israeli citizens on October 7th and advocate for the obliteration of Israel, has to go. It can no longer have operational control of Gaza,” he added.
Israel’s war in Gaza has killed more than 12,700 Palestinians, including more than 5,000 children and 3,250 women, according to the Palestinian health ministry. In one month, Israeli forces have imposed a total siege of the densely packed territory, carried out relentless airstrikes and artillery, captured large parts of the northern half and cut off electricity and water to the 2.3 million people who live there.
Israel says the goal of the operation, which was launched in response to the massacre of 1,200 people by Hamas just over a month ago, is to destroy the group entirely.
As the humanitarian crisis in Gaza has worsened, calls for a ceasefire have grown. The United Nations secretary general, Antonio Guterres, has warned that Gaza was becoming a “graveyard for children”, and that “the unfolding catastrophe makes the need for a humanitarian ceasefire more urgent with every passing hour”.
But despite the high civilian death toll, only one US Senator had called for a ceasefire until Mr Merkley’s announcement.
Senate Majority Whip and Judiciary Committee Chairman Dick Durbin, a Democrat representing Illinois, said he supported a ceasefire “at least in the context of both sides agreeing”.
“For example, the release of those who have been kidnapped should be part of this immediate release. That should be the beginning of it,” he told CNN.
Mr Durbin has not pushed other Democrats to join him, however.
“They’re taking their own approach to it, I respect it,” he told The Independent. “It’s a complicated issue, tough call. I made my decision.”
The Independent emailed every US senator to ask their position on a ceasefire in Gaza; only 20 responded, and no one besides Mr Durbin supported a ceasefire. Where possible, The Independent’s reporters asked senators in person for their comments.
Of the remaining senators, 19 have called for a humanitarian pause — a position the Biden administration also supports. At least 11 senators have come out in opposition to a ceasefire, and the remainder did not respond to The Independent’s request for comment.
The Biden administration, meanwhile, has continued to offer its unqualified support for Israel’s war, both practically and morally. President Joe Biden has asked Congress to approve $14.3bn in aid for Israel in the wake of the Hamas attack, much of which would be spent on air and missile defence.
President Joe Biden has also faced calls for a ceasefire from his own staffers. Hundreds of government workers and members of Mr Biden’s own campaign team have pressed the administration to support a ceasefire.
One letter from more than 400 administration employees, including political appointees and White House staff, spans several cabinet-level agencies and the president’s office.
The letter, according to NBC News, calls on the president to “urgently demand a ceasefire” and “call for de-escalation of the current conflict by securing the immediate release of the Israeli hostages and arbitrarily detained Palestinians” as well as “the restoration of water, fuel, electricity and other basic services” and “the passage of adequate humanitarian aid to the Gaza strip.”