Speaking at a news conference in Riyadh, Prince Mohammed said the counter-terrorism force was borne out of "the Islamic world's vigilance in fighting this disease [terrorism] which has damaged the Islamic world.
"Currently, every Muslim country is fighting terrorism individually... so co-ordinating efforts is very important."
The coalition would not just focus on fighting IS, he added. Few other details have been given.
The list of 34 members:
Saudi Arabia, Bahrain, Bangladesh, Benin, Chad, Comoros, Djibouti, Egypt, Gabon, Guinea, Ivory Coast, Jordan, Kuwait, Lebanon, Libya, Malaysia, Maldives, Mali, Morocco, Mauritania, Niger, Nigeria, Pakistan, the Palestinians, Qatar, Senegal, Sierra Leone, Somalia, Sudan, Togo, Tunisia, Turkey, United Arab Emirates and Yemen.