Ismail Haniyeh told a news conference on Wednesday that the Hamas-led government had raised money, but so far has not found a way to get it into the Palestinian areas.
"We have given alternative suggestions and plans, including what has been reported about sending the lists of the employees to the Arab League to have a direct transfer to their accounts," Haniyeh said, but "we even faced American pressure to prevent the direct transfer".
Haniyeh appealed to Arab leaders to face up to the Americans "to stop the siege imposed on the Palestinian people and to stop the political blackmail against the government".
He also called on Palestinian bankers to "show the necessary patriotism".
Banks have been hesitant to handle funds for the Palestinian Authority for fear of US sanctions.
At his news conference, Haniyeh also spoke out against a plan by Ehud Olmert, the incoming Israeli prime minister, to draw the border between Israel and the West Bank unilaterally if peace talks are unsuccessful, by completing a separation barrier, relocating tens of thousands of Jewish settlers and pulling out of large parts of the West Bank.
Israel's new government is to take office on Thursday.
"We are in favour of any Israeli withdrawal"
Palestinian prime minister
"We are in favour of any Israeli withdrawal," Haniyeh said.
"If they are going to leave our land, we are not going to run after them and ask them to come back. This does not mean we are going to accept a de facto policy."
Haniyeh brushed aside questions about accepting an Arab League plan that would offer Israel peace in exchange for a complete withdrawal from the West Bank and Gaza and an acceptable solution for Palestinian refugees.
"This era cannot take a new initiative," he said, blaming Israel for the impasse and repeating Hamas demands for Israeli withdrawal from the West Bank, release of prisoners and return of refugees to their original homes, all without offering peace to Israel.
Hamas also is engaged in new quarrel with Mahmoud Abbas, the Palestinian president, on power sharing.
Al Jazeera's Arabic web site quoted Mohammed Nazzal, a member of the Syria-based Hamas leadership, as saying a "two-headed regime" of Abbas and Hamas cannot continue, indicating Hamas might run a candidate against him.
In Gaza, Fatah spokesman Tawfiq Abu Khoussa accused Nazzal and other Hamas leaders of trying to increase tensions.
In the Al Jazeera interview, Nazzal complained that Abbas "is contributing to the siege by trying to withdraw the government's security and financial prerogatives".
Hamas accuses Abbas of illegally
assuming control over security
Abu Khoussa said Hamas speaks in two voices. "Inside (the Palestinian areas) they are talking about national unity, and there are many people outside who are trying to create instability and tensions."
He said Abbas' assumption of control over security was legal.
"It looks like Mr Nazzal has never read the basic law," Abu Khoussa said.
The Palestine Media Centre, linked to Fatah, said that Nazzal's threat to try to unseat Abbas could lead to increased tensions.
"The place (for) the dialogue is inside the homeland, and not in exile," it said.
Nazzal's policy would "lead to fomenting civil war and the collapse of all the achievements of our people".