WASHINGTON -- Former U.N. Secretary General Kofi Annan is warning that military intervention in Syria by the major powers won't work.

In comments to be aired Sunday on CNN's "Fareed Zakaria GPS," Annan says the situation in Syria is more complex than in Libya, and that military intervention could make things worse.

Annan was the special envoy to Syria until August, when he resigned after his peace plan failed. That led Republican Paul Ryan to say in the vice presidential debate that the U.S. shouldn't have waited for Annan to develop an agreement and that the delay had bought Syrian President Bashar Assad more time.

Annan says Ryan is, quote, "dead wrong." He says raising the hopes of the Syrian people while other countries are still reluctant to intervene complicates the situation.

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  • Standing in front of a row of plastic tents a young boy flashes the V-sign in a refugee camp on the border between Syria and Turkey near the northern city of Azaz on December 5, 2012. The internally displaced faced further misery as heavy rain was followed by a drop in temperatures. The United Nations estimated late October that more than 2.5 million people have been affected by the fighting in Syria. There are more than 348,000 Syrian refugees registered in neighbouring countries, but many more are unregistered. Credit: ODD ANDERSEN/AFP/Getty Images

  • Syrian refugees react as United Nations Secretary General Ban Ki-Moon (unseen) arrives for a visit in the Zaatari Refugee Camp, on December 7, 2012. UN chief Ban Ki-moon appealed Friday for more aid to help hundreds of thousands who have fled the Syrian conflict, as he visited a refugee camp in neighbouring Jordan.(KHALIL MAZRAAWI/AFP/Getty Images)

  • A Syrian boy, who fled his home with his family due to fighting between government forces and rebels, stands near his tent at a refugee camp near the Turkish border, Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • An elderly Syrian woman, who fled her home with her family due to fighting between government forces and rebels, chants, "Allah," meaning God in Arabic, inside her tent at a refugee camp near the Turkish border, in Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • A Syrian woman, who fled her home with her family due to fighting between government forces and rebels, stands near her tent at a refugee camp near the Turkish border, Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • A Syrian man, who fled his home with his family due to fighting between government forces and rebels, plays with his nephew near their tent at a refugee camp near the Turkish border, Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • Syrian women, who fled their homes due to fighting between government forces and rebels, drink tea inside their tent at a refugee camp near the Turkish border, Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • Syrians, who fled their homes with her families due to fighting between government forces and rebels, sit in their tent at a refugee camp near the Turkish border, Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • Syrias, who fled their homes with their families due to fighting between government forces and rebels, take refuge at a camp near the Turkish border, Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • A Syrian woman, who fled her home with her family due to fighting between government forces and rebels, sits near her tent at a refugee camp near the Turkish border, in Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • A Syrian girl, who fled her home with her family due to fighting between government forces and rebels, flashes the victory sign at a refugee camp near the Turkish border, Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • A Syrian boy, who fled his home with his family due to fighting between government forces and rebels, plays near his tent at a refugee camp near the Turkish border, Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • Syrians, who fled their homes with their families due to fighting between government forces and rebels, wait for food distribution from an NGO at a refugee camp near the Turkish border, in Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)

  • A Syrian boy, who fled his home with his family due to fighting between government forces and rebels, holds a plate with food to eat at a refugee camp near the Turkish border, Azaz, Syria, Sunday, Oct. 7, 2012. (AP Photo/ Manu Brabo)