Pakistan has confirmed it's part of a Saudi-led "Islamic military alliance" against terrorism in the Muslim world but remained vague about when exactly it joined the new alliance.

Foreign Office spokesman Qazi Khalilullah told reporters Thursday in Islamabad that, "yes, we're part of it."

He also denied media reports from Wednesday that claimed Pakistan was "surprised" when its membership in the 34-nation group was announced on Tuesday. He insisted Foreign Secretary Aizaz Ahmad Chaudhry had earlier only said that Pakistan was "ascertaining details" about the announcement.

Khalilullah went on to say that Pakistan and Saudi Arabia have been exchanging ideas on how to deal with terrorism.

The new coalition does not include Shiite-led countries of Iran, Iraq and Syria, raising questions whether it can be a unified front against extremists.