BEIRUT/AMMAN: Anxious to keep Syria’s civil war from spiraling into even worse problems, President Barack Obama said Friday he worried about the country becoming a haven for extremists when – not if – President Bashar Assad is ousted from power.

Obama, standing side by side with Jordan’s King Abdullah II, said the international community must work together to ensure there was a credible opposition ready to step into the breach.

“Something has been broken in Syria, and it’s not going to be put back together perfectly immediately – even after Assad leaves,” Obama said. “But we can begin the process of moving it in a better direction, and having a cohesive opposition is critical to that.”

He said Assad was sure to go but there was great uncertainty about what would happen after that.

“I am very concerned about Syria becoming an enclave for extremism,” Obama said, adding that extremism thrived in chaos and failed states. He said the rest of the world had a huge stake in ensuring that a functioning Syria emerged.

“The outcome is Syria is not going to be ideal,” he acknowledged, adding that strengthening a credible opposition was crucial to minimizing the difficulties.

Obama, at a joint news conference with Abdullah, said his administration was working with Congress to provide Jordan with an additional $200 million in aid this year to cope with the massive influx of refugees streaming into the country from Syria.

Abdullah said the refugee population in his country had topped 460,000 and was likely to double by the end of the year – the equivalent of 60 million refugees in the United States, he said.

Obama, who arrived in Amman Friday, also said he would “keep on plugging away” in hopes of getting the Israelis and Palestinians to reach a peace agreement.

In Syria, Assad vowed to purge Syria of “extremist forces” he accused of assassinating a leading Sunni preacher who backed his 2-year-old battle against rebels and protesters.

He made the pledge in a message of condolence over the death of Mohammad al-Buti, who was killed along with dozens of worshippers by an explosion in a Damascus mosque Thursday.

State media put the death toll from the blast at 49, but the Britain-based activist group Syrian Observatory for Human Rights, which monitors violence across the country, said 52 people died and the final figure was likely to be more than 60.

Authorities announced a day of mourning Saturday, when a funeral is expected to be held for Buti, who often delivered his sermons in the historic Umayyad Mosque.

“Your blood ... and that of all Syrian martyrs will not be shed in vain,” Assad said. “We will adhere to your thinking to eliminate their darkness and extremism until we purge our country of them.”

The mosque bombing took place in the Mazraa district of central Damascus, where a car bomb killed more than 60 people one month ago, another sign that Syria’s civil war had penetrated to the heart of Assad’s capital.

Assad’s artillery positions on the northern edge of Damascus pounded the rebel-held southwestern towns of Daraya and Moadamieh Friday and a Damascus resident said the smell of gunpowder hung over the city center.

The United Nations Security Council “condemned in the strongest terms the terrorist attack in a mosque in Damascus,” but added that any steps to combat terrorism must comply with international law on human rights and refugees. Opposition leader Ahmad Moaz al-Khatib, himself a former preacher at the Umayyad Mosque, said the killing of a Muslim scholar in a religious sanctuary was “a crime in every sense of the word.”

“We could not agree with him politically, and believed he was wrong to stand with the rulers, but his killing opens up the gates to an evil that only God knows,” he said in a statement.

Buti was a Sunni like most Syrians and the great majority of rebels, who were angered by his support for a president from the country’s Alawite minority.

In one of his televised speeches, Buti described those fighting to topple Assad as “scum.” The frail, 84-year-old preacher also used his position to call on Syrians to join the armed forces and help Assad defeat his rivals in the rebellion.

But Khatib said there had been signs Buti was questioning his support for Assad and suggested he may have been killed by authorities “who feared that if he took a courageous decision it could overturn the whole balance [of power].”

Opposition activists have frequently blamed Syrian authorities in the immediate aftermath of major bombings in Damascus, many of which have subsequently been claimed by the Nusra Front – a rebel group which the U.S. has designated a terrorist organization.

In Dublin, European Union foreign ministers displayed their divisions over whether to start shipping weapons to Syrian rebels, with Britain and France isolated in their efforts to boost the opposition’s firepower.

British Foreign Secretary William Hague said the European Union’s policy of providing only non-lethal equipment to the National Coalition must end if Syria’s primary opposition forces are to oust Assad from power.

“In order to support a diplomatic and political settlement which is essential for peaceful transition, it will be necessary for us to increase the support that we give to the National Coalition on the ground,” Hague said in comments mirrored by his French counterpart, Laurent Fabius.

But the other 25 EU ministers rallied behind the cautionary views of Germany, which argues that increased aid to rebel-held areas should be confined to improving their access to water, power, food and medical care.

German Foreign Minister Guido Westerwelle said he accepted that Britain, France and the U.S. had “good reasons” for wanting to increase the ability of opposition forces to defeat Assad’s military. But he warned that sending weapons was likely to have unintended and negative consequences. He said more civilians would be killed in crossfire, and Western-supplied weapons could end up in the hands of anti-Western jihadists like Nusra.

“We are still reluctant on lifting the arms embargo,” Westerwelle said. “We have to avoid a conflagration and we have to prevent that aggressive offensive weapons come into the wrong hands.”

Several other foreign ministers publicly backed Westerwelle’s reservations as they entered the Dublin Castle talks, which conclude Saturday. All emphasized that the EU would not consider easing its arms embargo on Syria until the end of May, when the existing restrictions are due to expire.

Hague said Britain and France reserved the option of moving ahead on their own, but would greatly prefer to have a united EU position.

EU foreign ministers last month did amend the bloc’s embargo rules on Syria to permit shipments of nonlethal equipment to rebels. Britain and France have begun shipping armored cars, night-vision goggles, body armor and other overtly military equipment under terms of that amendment.

The relatively lightly armed anti-Assad forces say they most desperately need ground-to-air weapons to deter government air strikes and helicopter gunships, as well as increased access to anti-tank weaponry.