Dahlan, a former Gaza security chief, said in a phone interview with the AP news agency published on Sunday that he expected the quietly negotiated agreement to lead to opening the blockaded Palestinian territory's border with Egypt in late August and an easing of crippling power outages.
Funding has been secured from the UAE for a $100m power plant to be built on the Egyptian side of the border, said Dahlan from the United Arab Emirates.
Several dozen of Dahlan's lieutenants and key supporters are expected to return from exile as part of the arrangements. But he said he will remain in exile.
"It's better for Gaza that I stay in the diaspora and approach everyone who can extend a helping hand to Gaza," Dahlan said.
The 55-year-old said his chemistry with Gaza's newly-elected Hamas chief, Yehiyeh Sinwar, helped forge the once-unthinkable alliance backed by Egypt and the UAE.
The two grew up in the streets of southern Gaza's Khan Younis refugee camp before joining rival camps, Hamas and the mainstream Fatah movement, respectively.
"We both realised it's time to find a way out" for Gaza, Dahlan said in an hour-long conversation on Saturday.
The deal, which gives Dahlan a chance to return to Palestinian politics, is still in the early stages of implementation.
Abbas has a toxic relationship with Hamas, which seized Gaza from him in 2007, and with Dahlan, a former top aide.
The objectives of the Dahlan-Hamas deal - ending the border blockade, reviving Gaza's battered economy - could also weaken Palestinian statehood aspirations by creating a "mini-state" in Gaza.
Dahlan dismissed concerns that his deal with Hamas will gradually turn Gaza into a separate entity.
"We are patriots, not separatists," he said, adding that he would do everything in his power to prevent a further drifting apart of the Palestinian territories.
The multi-millionaire with far-flung business interests in the region and close ties to leaders of Egypt and the UAE said he no longer aspires to replace Abbas.
"I have no ambitions to be president," he said. "Maybe that was the case when I was younger, but now I see the situation: 70 percent of the land is in the hands of the Israelis, and they have no intentions to give us a state."
Azzam al-Ahmed, an Abbas aide who negotiated with Hamas in the past, said on Sunday that the Dahlan-Hamas understandings "are going nowhere".
He said Abbas' Palestinian Authority supports Gaza with $1.2bn every year, covering wages of ex-loyalists, social welfare payments and electricity. He suggested Dahlan and Hamas would be unable to cover such sums.
Al-Ahmed also said Egypt assured Abbas "that they are not going to help any new entity in Gaza".
However, the lengthy negotiations between Dahlan's representatives and a Hamas team in Cairo last month would not have been possible without Egypt's blessing, participants said.
Source: AP news agency