Football's world governing body's Ethics Committee ruled that both FIFA president Blatter and his UEFA counterpart Platini had broken FIFA Code of Ethics relating to conflicts of interest, breach of loyalty and gifts. The pair were cleared of bribery and corruption allegations.
Blatter said he was being treated like a "punching ball" and maintained he was still the FIFA President and "a man of principles."
"I'm really sorry. I'm sorry. I'm sorry that I am still somewhere a punching ball," the 79-year-old said at a press conference at FIFA's former headquarters at Sonnenberg, Zurich.
"I'm sorry for me for, how I'm tainted in this world of humanitarian qualities," Blatter added.
"Even suspended I am the President. I am not ashamed. I [do] not regret ...
"I will always repeat that. I am a man of principles. These principles are never taking money you have never earned and pay your debts."
Blatter also claimed FIFA's Ethics Committee has no right to go against him and said he would be appealing the ban.
"We will go once again to the Appeal Committee," he said. "I'm a Swiss citizen. In the Swiss law you wouldn't be suspended for eight years -- you will have had to commit something very, very important."
"I am fighting not for me, but as the elected President of FIFA ... and they have cut me off," Blatter added. "We have to defend ourselves, I hope Platini feels the same."
Platini announced later in the day that he too would be appealing the ban, while UEFA (European football's governing body) also issued a statement backing its President.
"This decision does not surprise me. The procedure committed by FIFA's Ethics Committee against me is a real masquerade," read a statement issued by Platini.
"FIFA's Ethics Committee is designed to smear my name and which today I deny its very legitimacy and credibility.
"I am convinced that my fate was sealed before the hearing of December 18 and that this verdict is just a pathetic cover-up for a desire to eliminate me from the world of football.
"Parallel to going to the Court of Arbitration for Sport, I am determined to apply to, at the right time, civil courts to obtain damages for all the prejudice I have suffered over very long weeks. I will keep fighting until the end of this process.
"On the football field and in the exercise of my mandates, my behaviour has always been irreproachable and I am, for my part, at peace with my conscience."
UEFA added in a separate statement: "UEFA has taken note of the decision of the FIFA Ethics Committee to suspend Michel Platini for eight years from all football-related activities.
"Naturally, UEFA is extremely disappointed with this decision, which nevertheless is subject to appeal.
"Once again, UEFA supports Michel Platini's right to a due process and the opportunity to clear his name."
FIFA, when contacted by CNN, said it "acknowledges the decisions of the independent Ethics Committee and has no further comment."
Ethics Committee announces ban
FIFA's Ethics Committee announced Monday that both Blatter and Platini would be suspended via an official statement.
"The adjudicatory chamber of the Ethics Committee chaired by Mr Hans‑Joachim Eckert has banned Mr Joseph S. Blatter, President of FIFA, for eight years and Mr Michel Platini, Vice-President and member of the Executive Committee of FIFA and President of UEFA, for eight years from all football-related activities (administrative, sports or any other) on a national and international level," the FIFA statement read.
"The bans come into force immediately."
The pair had disciplinary hearings before FIFA ethics judge Hans-Joachim Eckert in Zurich Thursday and Friday over a $2 million payment made to Platini in 2011 by world football's governing body and signed off by Blatter.
Both men denied any wrongdoing.
Blatter and Platini, who faced charges including corruption, conflict of interest and non-cooperation, had said the payment was honoring an agreement made for work carried out between 1999 and 2002, when Platini worked as a technical adviser for the FIFA president.
"The payment to Mr Platini had no legal basis in the written agreement signed between both officials on 25 August 1999," the Ethics Committee ruled.
"Mr Platini's assertion of an oral agreement was determined as not convincing and was rejected by the chamber," the FIFA statement added.
Blatter and Platini were provisionally suspended
by FIFA for 90 days in October -- alongside FIFA Secretary General Jerome Valcke -- with both immediately appealing the decision.
Platini, who refused to attend his hearing in protest, took a case to the Court of Arbitration for Sport (CAS) earlier this month, but saw his suspension upheld
Platini, who enjoyed a successful career as a player for Juventus and France, was hoping to replace Blatter as the head of FIFA at the February 26 election, however, the ban looks likely to have killed off his chances.
Blatter, FIFA boss since 1998, announced in June
he would be stepping down in time for the next election.
The pair could decide to challenge the decision at the FIFA Appeal Committee -- as Blatter has confirmed -- and then at CAS.
FIFA has been besieged by crisis ever since seven of its members were arrested
and 14 senior executives charged in May shortly before Blatter won a fifth term in office.
Extraditions and criminal charges followed as federal prosecutors in the United States continued its investigations while Swiss authorities quizzed Blatter
on suspicion of "criminal mismanagement."