The United Nations has said that if the conflict in Syria continues at its current pace the number of people requiring humanitarian assistance within the country would rise by 1.5 million by early next year.
In an interview ahead of Friday's fifth Syrian Humanitarian Forum in Geneva, John Ging, operations director for the UN humanitarian office, has said the number of the Syrians that would need some form of humanitarian aid could increase from 2.5 million to four million by early 2013.
"People need to be aware of just how desperate the situation is inside Syria for the people there, how unbearable it is, and how they are suffering and falling into ever deeper despair and humanitarian need ... It's just getting a lot worse very rapidly for the ordinary people", Ging said.
Ging also said UN projections saw the number of Syrian refugees in neighbouring countries reaching 700,000, up from the current estimated 400,000 in early 2013.
Of the 2.5 million Syrians currently in need of humanitarian aid in Syria, Ging said the United Nations and other organisations were only able to reach 1.5 million. Funding was cited as one reason for the shortfall.
Programmes for Syrian refugees in camps in neighbouring countries, including Turkey, Lebanon and Jordan, are also seriously underfunded, said Ging. Donors have so far provided only 50 per cent of the amount needed, he said.
The UN humanitarian projections come as Syrian opposition figures are meeting in the Qatari capital, Doha, to forge a broad-based leadership group sought by the international community.
Riad Seif, a prominent dissident who had proposed a Western-backed initiative to unite the opposition and form a transitional government, said on Thursday that he was "optimistic" an agreement could be reached.
The opposition is moving towards creating "a political leadership that would satisfy the Syrians and be recognised by the international community," Seif said.
He later added that the main opposition bloc, the Syrian National Council (SNC), had deferred a decision until after a final round of internal elections. The bloc on Friday has elected an 11-member executive committee, who will in turn elect a leader.
The SNC is hesitant since it would reportedly be given only 22 of 60 seats in the new group, to make room for activists from inside Syria.
Al Jazeera's Omar Al Saleh, reporting from Doha, said it was obvious from Thursday's drawn-out negotiations that the Syrian opposition remain divided, with "huge differences between the members of the Syrian National Council and other opposition figures".
"The international community and the core group of the 'Friends of Syria' that includes the US, France, Britain, Qatar, Saudi Arabia, as well as Turkey, are pushing for a new initiative to be adopted by the delegates," he said.
"That initiative calls for a coherent representative structure that would also represent those fighting inside Syria. Western diplomats are telling Al Jazeera that this is not going to happen any time soon."
Washington wants the opposition to reshape into a "government-in-exile".
Opposition leaders say such a body could be sited outside Syria or in zones now under rebel control.
Hamad Bin Jassim Al Thani, prime minister of Qatar, urged Assad's opponents to "unify their ranks and positions and to prioritise the interests of their nation and people over their own personal interests".
The search for a united front came as a video emerged purporting to show rebel fighters shooting dead an unarmed man.
The United Nations and human rights groups say both pro-government and anti-Assad fighters are guilty of war crimes - and the latest video would appear to give more evidence for that.
"It shows the ugliness of the war," said Middle East analyst Joseph Kechichian. "Obviously this is a civil war going on and there are breaches of international conduct and human conduct ... This is not the first time and not the last. Unfortunately, we are going to see these more often."
Reacting to the footage, SNC's Radwan Ziadeh said: "It's a very shocking video and alarming." "We condemn all the human rights violations committed by the rebels or FSA [Free Syrian Army]. [But] we are not sure that who did this execution are members of the FSA."
Assad vows to stay
| SNC's Radwan Ziadeh speaks to Al Jazeera about
war crimes allegations raised against rebels
Meanwhile, a defiant Bashar al-Assad, Syrian president, rejected calls he seek a safe exit from the country, pledging he would "live in Syria and die in Syria".
"I am not a puppet. I was not made by the West to go to the West or to any other country," Assad said in English in an interview with Russia's RT television.
"I am Syrian, I was made in Syria, I have to live in Syria and die in Syria," he said, according to transcripts posted on RT's website.
On Tuesday, David Cameron, British prime minister, floated the idea of granting Assad safe passage from the country, saying it "could be arranged," although he wanted the Syrian leader to face international justice.
Assad also warned against foreign intervention in the country's escalating conflict, saying such a move would have global consequences and shake regional stability.
"We are the last stronghold of secularism and stability in the region ... it will have a domino effect that will affect the world from the Atlantic to the Pacific," the transcript said.
In a separate video extract of the interview, Assad added: "The price of this invasion, if it happens, is going to be big, more than the whole world can afford."