Palestinian militant group Hamas accused the US today of putting pressure on rival Palestinian groups to refuse to enter coalition government.
But President Mahmoud Abbas's mainstream Fatah movement and other PLO factions denied bowing to US pressure and said serious differences over Hamas' political programme prevented them from joining the new government.
Hamas's failure to attract any partners and its move to appoint Hamas loyalists to top ministerial posts could bolster US and Israeli efforts to isolate the new government.
The group's leader-in-exile Khaled Meshaal, in Yemen as part of a tour to drum up political and financial support, said the Israelis could use Hamas's isolation in government as a pretext to launch strikes at Palestinians.
"The United States placed pressure on ... Palestinian factions to not participate in the government so that the government will be purely Hamas and Israel can justify carrying out its plan to attack the Palestinian people," Mr Meshaal said.
Palestinian Prime Minister-designate Ismail Haniyeh gave the names of his cabinet to Mr Abbas late last night after Hamas failed to persuade rival factions to join.
Fatah and independent parliamentary blocs have demanded a Hamas-led government accept peace deals with Israel.
The Marxist Popular Front for the Liberation of Palestine and the Democratic Front for the Liberation of Palestine wanted Hamas to recognise the PLO as the sole representative of Palestinian people everywhere and accept its policies.
"There was no pressure on us from the United States to refrain from joining the government. We refused to join because we have serious problems with Hamas' political programme," Azzam al-Ahmad, head of the Fatah parliamentary bloc said.
"We can't join a government that refuses to recognise the PLO as the sole, legitimate representative of the Palestinian people and rejects the PLO's international commitments."
Israel and the United States have called on other countries to boycott Hamas, which crushed Mr Abbas's long-dominant Fatah faction in January parliamentary polls, until it disarms and recognises the Jewish state and interim peace deals.