RAMALLAH (Reuters) - US President Barack Obama is an unlikely participant in a Palestinian campaign to drum up support for a bid to win UN recognition of their statehood -- a diplomatic move opposed by both his administration and Israel.

But as part of an official media campaign begun this week, Palestinians have pulled from the archive some words spoken by Obama during the 2010 UN General Assembly, in which he alluded to the prospect of a Palestinian state joining the world body.

"When we come back here next year, we can have an agreement that can lead to a new member of the United Nations, an independent, sovereign state of Palestine living in peace with Israel," Obama says in his 2010 speech.

Although described by US officials as no more than an expression of hope, the Obama remarks are one factor cited by Palestinians when explaining their push for U.N. membership at this year's General Assembly, due to convene in a few weeks.

"If he said it, he must have meant it," President Mahmoud Abbas says during a 36-second radio spot.

The ad is a reflection of Palestinian frustration with the Obama administration. The Palestinians feel Obama let them down, notably by failing to convince Israel to halt Jewish-only settlement expansion in the West Bank and East Jerusalem -- part of the territories where they seek an independent state.

Though the US president's remarks were hedged, Abbas has described the statement as the "Obama promise."

Obama spoke just a few weeks after his administration had brokered a resumption of peace talks, which then collapsed a few weeks later over the settlement issue.

The US president's words are being used alongside excerpts of speeches by the late Palestinian leader Yasser Arafat as part of the campaign. Verses penned by Mahmoud Darwish, the national poet who died in 2008, also feature.

The United States, Israel's closest ally, opposes the Palestinian UN initiative on the grounds that it is unhelpful to its Middle East diplomacy, which is still focused on bringing about a resumption of face-to-face peace talks.

US opposition in the Security Council will thwart any Palestinian bid for full UN membership, although the Palestinians could still secure an upgrade in their status to a "non-member state" by presenting a General Assembly resolution.

"We are reminding [Obama] of what he said in the United Nations in 2010," said Ahmad Zaki ElAreedi, director of Voice of Palestine radio, one of the Palestinian Authority-run institutions broadcasting the campaign.

Western diplomats have pinned much of the blame for the moribund peace process on Israel, with Washington and European capitals roundly condemning a spurt of recent approvals for settlement building in East Jerusalem and the West Bank.

While the United States has said it will side with Israel in the impending showdown in the United Nations, a big majority of UN members are likely to back the Palestinians.