More than 2,000 demonstrators gathered outside the United Nations' offices in Beirut on Tuesday in a show of support for a Palestinian bid to secure full UN membership.

"We are here to show our support for Palestine's right to be recognised as a state, a right that is stipulated by international law," said Kazem Hassan, one of the organisers of the joint rally by Lebanese and Palestinians.

The demonstrators gathered outside the UN building in Beirut's commercial district, waving Lebanese and Palestinian flags as well as banners reading "Palestine, the 194th state in the United Nations".

They also raised pictures of Palestinian president Mahmud Abbas and late leader Yasser Arafat.

Abbas, acting in his capacity as head of the Palestine Liberation Organisation, has vowed to formally submit the membership bid to the UN on Friday, when he will also address the General Assembly.

Abbas has said he is determined to go ahead with the controversial move despite mounting international pressure against it.

There are an estimated 300,000 Palestinian refugees in Lebanon, according to officials.

From another side, Palestinian foreign minister Riyad al-Maliki on Tuesday called on the United States to "change its position" on the Palestinian bid to become a full UN member as a state.

"I hope that the United States will change its position and follow the majority of countries which want to support the Palestinian right to self-determination and an independent state," Maliki said after meeting his Venezuelan counterpart.