The U.N. Security Council on Saturday unanimously called for a 30-day cease-fire in Syria, with Russia agreeing to the temporary hiatus only after forcing two days of delays that critics said allowed ally Syrian President Bashar al-Assad to pursue a renewed bombing campaign blamed for hundreds of recent deaths in a rebel-controlled area.

The nationwide truce would begin “without delay,” a victory for the United States and other nations that resisted Russian efforts to push back the start or soften the terms.

It came after intense negotiations to persuade Russia not to use its veto power in the Security Council. Moscow had blocked 11 previous Syria resolutions. The United States and others accused Moscow of protecting the Assad government and its bombing campaign in the Damascus suburb of Eastern Ghouta while allowing a humanitarian disaster to continue.

There was a further delay Saturday as Russia and the United States haggled behind closed doors over the final text. Cameras in the Security Council chamber captured other delegates poring over the document shortly before the session finally began, more than two hours behind schedule.

Nikki Haley, the U.S. ambassador to the United Nations, said little had changed during the arduous negotiations, “except a few words and some commas.” She blamed Russia, Syria and Iran for not taking moral responsibility for the urgency of the situation.

“As they dragged out the negotiation, the bombs from Assad’s fighter jets continued to fall,” she said. “In the three days it took us to adopt this resolution, how many mothers lost their kids to the bombing and shelling? How many more images did we need to see of fathers holding their dead children?

“All for nothing, because here we are voting for a cease-fire that could have saved lives days ago.”

It will be up to Russia to use its influence with Assad to enforce the cease-fire, which would allow desperately needed deliveries of emergency supplies and medical evacuations of the seriously injured and sick.

Activists and monitors say that more than 500 civilians have been killed in the past week in Eastern Ghouta in what is considered the fiercest assault in seven years of civil war. Each day of delay in imposing the cease-fire allowed Assad’s forces to destroy more of the largely rebel-controlled area.

The humanitarian convoys “are ready to go,” Swedish Ambassador Olof Skoog told the council.

It was not at first clear when the cease-fire would take effect. The United States had wanted the agreement to apply right away, which Russian Ambassador Vassily Nebenzia called unrealistic.

Speaking through an interpreter, Nebenzia urged a “concrete agreement for the warring parties in Syria.” He did not directly address the current humanitarian crisis.

Nebenzia said the United States should focus on trying to end the war and halt “dubious” intervention efforts, “instead of scaling up rhetoric against Russia.”

“I cannot even count the number of statements by U.S. Ambassador Haley, how many times that the name Russia was mentioned.”

“This ended up being a bit of a showdown” between Haley and Nebenzia, said a Security Council diplomat who spoke on the condition of anonymity to describe the backroom negotiations.

“She succeeded in retaining vital language in the resolution that called for an immediate start to the cease-fire and unfettered humanitarian access without delay. The Russians kept trying to water it down.”

On Friday, a vote was scheduled, and delayed, three separate times before diplomats gave up the effort after sundown.

One sticking point was when the cease-fire would begin. The draft submitted Friday night by Kuwait and Sweden did not give a specific start time.

The resolution would demand “that all parties cease hostilities without delay for at least 30 consecutive days throughout Syria for a durable humanitarian pause, to enable the immediate delivery of humanitarian aid and services and medical evacuations of the critically sick and wounded.”

It would encourage efforts toward a longer cease-fire, but it does not set terms for that goal.

It also would carve out an exception for military action against the Islamic State, al-Qaeda and other terrorist groups.

Some diplomats suspect that Russia was stalling a vote to allow Syria’s warplanes to continue the country’s offensive against rebels with missiles, mortars and barrel bombs.

Hospitals also have been hit, and the pleas coming from some of the 400,000 residents of the area have grown increasingly desperate.in the face of what U.N. officials describe as a medieval siege. U.N. Secretary General António Guterres labeled conditions in Eastern Ghouta “hell on earth.”

“Our government has the right to defend itself,” Syria’s ambassador to the United Nations, Bashar Jaafari, told the council. Syria considers the anti-Assad rebels to be terrorists. Other terrorist groups have exploited the civil war to gain ground in Syria.

Jaafari said the United States, Britain and France are improperly attempting to dictate to Syria, while engaging in what he called improper military intervention around the world.

“We are exercising the sovereign right of self-defense within our national borders,” he said. Syria has attempted to evacuate civilians from Eastern Ghouta, he said.

World leaders appealed to Russia to back the truce allowing a temporary reprieve from the bombardment.

President Trump accused the Syrian government and its backers, Russia and Iran, of being responsible for a humanitarian “disgrace.”

French President Emmanuel Macron and German Chancellor Angela Merkel appealed in a joint letter to Russian President Vladimir Putin to back a cease-fire.

But the difficulties encountered by the Security Council to pass a cease-fire resolution in the face of such human suffering underscored some the institution’s impotence.

“This is not a moment for self-congratulation,” said Stephen Hickey, an official with the British mission to the United Nations. “It has taken us far too long. While we have been arguing over commas, Assad’s planes have been killing more people in their homes and their hospitals, imposing unbearable suffering.”

Some expressed hope that the truce could provide momentum for political talks and a negotiated end of the war.

“Our generation will be judged by whether we manage to put an end to the Syrian tragedy,” said Francois Delattre, France’s U.N. ambassador.

“There is a glimmer of hope today,” he added. “Let us manage to seize on this fragile moment.”