The kingdom signed an agreement with the United Nations in 2011 to create the centre, and the government has already given US$10m towards its launch.
"I announce a donation from the kingdom of Saudi Arabia of US$100 million to support this centre and work for its activation under the umbrella of the United Nations," King Abdullah said in a joint message with Crown Prince Salman marking Eid Al Fitr reported by official news agency SPA.
The king, who proposed the creation of a counter-terrorism centre in 2005, urged the international community to support the institution in order "to get rid of the forces of hatred, extremism and criminality". "Terrorism threatens global peace and stability" and in efforts to fight it, no leniency should be shown towards militants or their funders, the king said.
"We should understand that terrorism will not disappear within a limited period. So we have to be prepared for a long fight with terrorism. Whenever we try to tighten the noose it could become increasingly aggressive and violent. But we have strong faith in God that it would be defeated," the Arab News, published in Jeddah, quoted the message as saying.
In their joint message, King Abdullah and Prince Salman warned against the political motives of terrorist ideologies and against those who distort the meaning of religious texts to suit "their vested interests." Those who misinterpret the texts tarnish the image of Islam and its values and principles, the message said, according to the newspaper.
"We should stand firm against the proponents of sedition, deviation and distortion," the message added.
Meanwhile, the Reuters news agency has reported that the Saudi government has offered Russia economic incentives - including a major arms deal and a pledge not to challenge Russian gas sales - if Moscow scales back support for the Syrian government of President Bashar Al Assad.
The proposed deal between two of the leading power brokers in Syria's civil war was set out by Saudi intelligence chief Prince Bandar bin Sultan at a meeting with Russian President Vladimir Putin in Moscow last week, they said.
According to Reuters, Syrian opposition sources close to Saudi Arabia said Prince Bandar offered to buy up to US$15 billion of Russian weapons as well as ensuring that Gulf gas would not threaten Russia's position as a main gas supplier to Europe. Russia has supported Assad with arms and diplomatic cover throughout the war and any change in Moscow's stance would remove a major obstacle to action on Syria by the UN Security Council.