The Supreme Leader of Iran, Ayatollah Ali Khamenei, has called on the Muslim world to help the Palestinian people and their Hamas-led government.
Both he and President Mahmoud Ahmadinejad launched strong attacks on the West as a three-day forum on Palestinian solidarity began in Tehran.
The US Treasury has this week further tightened Palestinian cash flows.
But Palestinian PM Ismail Haniya said on Friday the cuts in funds would not weaken the people's resolve.
Late on Friday, the Russian Foreign Ministry said Moscow had agreed to provide "urgent financial aid" to the Palestinian Authority.
The US and European Union cut off aid to the authority after Hamas took power on 30 March, because the militant group refuses to renounce violence and recognise Israel.
'Rotten tree'
Ayatollah Khamenei, opening the Tehran conference, said all Muslims had a duty to help the Palestinian people and should not remain indifferent to tyranny.
"The chain of plots by the American government aimed at governing the Middle East through the control of the Zionist regime will not succeed"
He launched a scathing attack on the West, saying its liberal democracy was like a poison.
He said global imperialism led by the US president openly threatened the Muslim world by talking about launching a crusade against it
President Ahmadinejad widened the attack to include Israel, which he said was "a rotten, dried tree that will be eliminated by one storm".
The president provoked an international outcry last October when he cast doubts on the Holocaust and said Israel should be "wiped off the map".
On Friday he said there were no doubts about the holocaust suffered by the Palestinian people in the past 60 years and that the Palestinians should not pay the price for what the West said were crimes against Jews.
"Believe that Palestine will be freed soon," he said.
The conference came as the US Treasury banned its nationals from doing business with the Hamas-led Palestinian Authority.
It said the militant Islamist group had a vested interest in the transactions of the authority.
The US is making exceptions for government entities under the direct control of Palestinian Authority President Mahmoud Abbas, whose Fatah movement is a rival of Hamas.
'Oil and olives'
Mr Haniya said on Friday the suspension of Western aid to the Palestinians would never defeat the Hamas-led administration.
He said the West would not succeed in isolating the government because it had the full support of Palestinians.
"We will eat cooking oil and olives," he said.
Mr Haniya was addressing Friday prayers in Gaza before the start of a series of rallies aimed at demonstrating support for the Hamas-led administration.
In response to the financial crisis, the Russian foreign ministry said Moscow would grant the Palestinian Authority urgent financial aid.
Foreign Minister Sergei Lavrov made the pledge to Mr Abbas in a telephone call, a ministry statement said.
Russia says Hamas should recognise Israel and enter negotiations but it believes denying aid is a mistake.
The militant group's political leader in exile, Khaled Meshaal, is attending the Tehran conference to gain funding pledges.
Iran has said it will fund the Hamas-led government but so far no figures have been publicly pledged and no concrete deals have yet been announced at the conference.
^ Back to top | BBC Sport Home | BBC Homepage | Contact us | Help | ©
~RS~q~RS~~RS~z~RS~22~RS~)