JERUSALEM, Israel -- The U.S. Congress threatened to cut off aid to the Palestinian Authority after the P.A. announced it will form a unity government with Hamas. 

Both senior Republicans and Democrats said U.S. taxpayer funds cannot and should not be used to support a Palestinian unity government that includes the terrorist organization. 

An Obama administration official said the formation of any Palestinian government must accept three principles: renounce violence, abide by past agreements, and recognize Israel's right to exist. 

However, it's unlikely Hamas will accept those conditions.  Hamas is the Palestinian arm of the Muslim Brotherhood and its charter calls for the destruction of Israel.  
 
"Israel will arise and continue to exist until Islam abolishes it, as it abolished what went before," the charter reads. 

"According to this agreement, Hamas doesn't need to change its charter that calls for the destruction of Israel," said Israeli President Shimon Peres, who called the Hamas-Fatah unity deal a "fatal mistake."

"It is a branch of Iran that calls for the same thing," Peres continued. "There is a group of three -- Iran, Hamas and Hezbollah -- that want together to create a camp of war." 

Despite the alliances forged by Hamas, Palestinian President Mahmoud Abbas said he needs to include them.    

"Hamas are part of the Palestinian people," he said. "I cannot exclude them. They are a part, like or dislike.  Agree with them or disagree with them, they are part of our people." 

But Abbas chose unity with a Palestinian group most Western democracies have rejected. 

"According to U.S. law, Hamas is a terrorist organization," noted Mark Regev, a spokesman for Israel's prime minister. "According to Canadian law, Hamas is a terrorist organization. According to Australian law, Hamas is a terrorist organization. According to European Union, Hamas is a terrorist organization."
 
"This is a group that takes murderers and puts them up on a pedestal," he added. "This is a group that adheres to the murdering of children. They really are outside what anyone would consider decent company."

The deal has also raised fears Hamas could take over the West Bank from Fatah like it took over the Gaza Strip in 2007.