Al-Qaeda number two Ayman al-Zawahiri has called on the Palestinian militant group Hamas not to recognise past peace deals with Israel.
Zawahiri said the Palestinian Authority had betrayed its people
In a video message shown on Arab TV network al-Jazeera, Zawahiri urged Hamas, which won Palestinian elections in January, to fight on with arms.
Zawahiri also attacked the West for insulting the Prophet Muhammad in cartoons published in newspapers.
The drawings were deemed blasphemous by Muslims and sparked worldwide protests.
Al-Jazeera has not disclosed how it obtained the tape, the latest in a series of such video statements by Zawahiri intermittently broadcast by the channel.
Dressed in a black turban and white robe and seated in front of a curtain, Zawahiri accused the outgoing Palestinian administration of betrayal.
"No Palestinian has the right to give away a grain of the soil," he said.
"The seculars in the Palestinian Authority have sold out Palestine for crumbs... Giving them legitimacy is against Islam."
He called on Muslims in "Palestine, Iraq and everywhere else... [to] be wary of the new American game entitled the 'political process'", alluding to recent elections and democratic change.
Zawahiri urged Hamas to "continue the armed struggle" and reject agreements signed between its predecessors in government and Israel, describing them as "surrender accords".
Hamas leaders have dismissed Zawahri's comments.
Political leader Khaled Meshaal, speaking on the last day of a visit to Moscow, said the group did not need al-Qaeda's advice.
Hamas had its own vision, he said, and always acted in the interests of the Palestinian people.
Chief Hamas legislator Mahmoud al-Zahar denied his movement had "walked into a US trap" when it participated in the Palestinian elections.
"Entering these institutions does not mean that we will be a carbon copy of other factions, something that Mr al-Zawahiri warned of. Our position is very clear in this regard," he told al-Jazeera.
Strikes on West
In a reference to the cartoons of the Prophet Muhammad, Zawahiri said the West had committed deliberate blasphemy and was guilty of double standards.
"They did it on purpose and they continue to do it without apologising, even though no-one dares to harm Jews or to challenge Jewish claims about the Holocaust nor even to insult homosexuals."
He also singled out domestic Western policies he said discriminated against Muslims.
"In France a Muslim father cannot prevent his daughter from having sex because she is protected by the law, but this same law punishes her if she covers her hair," he said.
He called for strikes against Western nations, as well as Muslim governments he described as pro-Western - singling out Saudi Arabia, Jordan, Egypt, Pakistan and Tunisia.
"Inflict losses on the crusader West, especially to its economic infrastructure with strikes that would make it bleed for years," he urged.
"The strikes on New York, Washington, Madrid and London are the best examples," he said.