The documents sent thousands of people into the streets in Gaza City, angry with Palestinian negotiators for making concessions in peace talks, The Guardian reported.
Blair said it is too soon to know how much the documents will affect peace negotiations.
"I think it's hard to tell right now, but its intention was to be extremely damaging," Blair said. "I think we've just got to be big enough to say, OK, whatever al-Jazeera are putting out, we're going to get on with making peace."
Thousands of pages of documents covering over a decade of negotiations with Israel and the United States were obtained and released by al-Jazeera TV.
About 3,000 people took part in a rally in Gaza City organized by Hamas in support of anti-government protests in Egypt.
"We are here to deliver a message to the Palestinian Authority that they must come back to Palestinian ideas and reject the policies of American and Israel," said demonstrator Mahmoud Saleen.