Abbas accused Hamas, which controls the Gaza Strip, of jeopardizing a recently installed unity government, Egyptian media reported Sunday.
"We will not accept the situation with Hamas continuing as it is at the moment," Abbas said on arrival in Cairo late Saturday.
"We won't accept a partnership with them if the situation continues like this in Gaza where there is a shadow government... running the territory," he said.
The unity deal, inked on April 23, sought to end years of rivalry between the Fatah-dominated Palestinian Authority in the West Bank and the Islamist Hamas party in Gaza. Hamas took power in the coastal enclave following elections in 2007.
In June, Abbas swore in a national unity government in Ramallah, with Gaza's Hamas government officially stepping down the same day. Despite the handover, Hamas has remained the de facto power in Gaza.
His remarks came ahead of talks in Cairo with Egyptian President Abdel-Fattah el-Sissi and a key address to the Arab League.
He is also expected to brief the meeting on the situation in Gaza nearly two weeks after Hamas and Israel agreed to an open-ended ceasefire brokered by Egypt.
The deal ended 50-days of a devastating war in the enclave. More than 2,100 Palestinians and 70 on the Israeli side were were killed during the fighting. More than a quarter of Gaza's population of 1.8 million was internally displaced.
hc/se (AFP, dpa)