British Foreign Secretary William Hague on Thursday urged Syrian opposition groups to unite to halt extremists gaining influence in the country, as new leaders for the movement were elected in Doha.

Hague, speaking during a visit to India, said that opposition factions had to work together to end the conflict in Syria which erupted last year when protesters took to the streets to demand the fall of President Bashar Assad.

Turkey's President Abdullah Gul said Thursday that the country reserved the right to defend itself against any threat from neighboring Syria, amid discussions about the possible deployment of U.S. Patriot missiles.

"Patriots... are being discussed within NATO. It is only natural for us to take any measure for defense reasons," Gul told reporters, but insisted that it was "out of the question for Turkey to start a war with Syria.”

The humanitarian situation in Syria is now so bad that the Red Cross is struggling to cope, the new head of the international aid agency said Thursday.

"The humanitarian situation is getting worse despite the scope of the operation increasing," Peter Maurer, president of the International Committee of the Red Cross, told reporters in Geneva.

The main opposition Syrian National Council, under pressure to unite and bring in all parties, has elected a new leadership with Islamists heavily represented, SNC officials said on Thursday.

They said a president of the opposition coalition would be chosen on Friday, after the 40-member general secretariat was elected overnight at a meeting in the Qatari capital.

An Armenian plane carrying humanitarian aid for Syria was forced to land in Turkey on Thursday for an inspection of its cargo, the Anatolia news agency reported.

The cargo plane landed at Erzurum airport in eastern Turkey where teams of police and troops with sniffer dogs began their searches, it said.

Turkey said Wednesday it is in talks with NATO over the possible deployment of Patriot missiles on its soil amid the escalating conflict in neighboring Syria, but the prime minister insisted that no request has yet been made.

Foreign Minister Ahmet Davutoglu told reporters during a visit to Brussels that it was only "normal" to discuss any defense measures in the face of potential risk from Syria, according to the state-run Anatolia news agency.

More than 37,000 people have been killed since the outbreak of Syria's anti-regime revolt in March 2011, with over 1,000 dead in the past week, the Syrian Observatory for Human Rights said on Wednesday.

Civilians, at 26,596, represented the vast majority of those killed, said the Observatory, which included in that figure non-military people who have taken up arms against President Bashar Assad's regime.

Syria's foreign ministry warned Palestinians against becoming embroiled in the country's uprising on Wednesday, telling them to stay well clear of armed opposition groups, state television said.

"Syria will strongly oppose any attempt to bring the Palestinians into what is happening in Syria," a ministry source said, urging them to direct their efforts at the Palestinian cause, Syria TV reported.

Syria's main umbrella opposition group, under U.S. pressure to broaden its representation and urged by the Arab League to present a united front, began voting in a new leadership in Doha on Wednesday.

Some 400 members of the Syrian National Council were to choose from 29 lists of opposition groups ranging from liberals to the Muslim Brotherhood, as well as ethnic minorities and tribes.

Syrian President Bashar Assad's regime will not stay in power for long, Arab League chief Nabil al-Arabi said on Wednesday, urging the opposition meeting in Qatar to put aside their differences.

"It is important to unify the opposition's visions, especially because everyone knows that the regime in Syria will not remain for long and one day there will be a new situation in Syria," he told reporters in Cairo.