The World Health Organization said it is targeting 22 million children in the Middle East for polio vaccination after 13 cases of polio were confirmed in Syria.

In a joint resolution, all countries of the WHO Eastern Mediterranean Region -- Afghanistan, Bahrain, Djibouti, Egypt, Iran, Iraq, Jordan, Kuwait, Lebanon, Libya, Morocco, Oman, Pakistan, Qatar, Saudi Arabia, Somalia, Sudan, Syrian Arab Republic, Tunisia, United Arab Emirates and Yemen -- declared polio eradication to be an emergency and called on Pakistan to urgently access and vaccinate all of its children to stem the international spread of its viruses.

Pakistan is one of a handful of countries that had not eradicated polio before this outbreak in Syria in October. However, WHO officials had said earlier that the Syria outbreak came from a strain that originated in Pakistan.

The countries also called for support in negotiating and establishing access to those children who are currently unreached with polio vaccination.

Dr. Jaouad Mahjour, director of communicable diseases prevention and control at WHO's Eastern Mediterranean Regional Office, stressed the necessity of reaching all children inside Syria and in neighboring countries.

"WHO and UNICEF are coordinating the vaccination campaign with all concerned parties to make sure that all children are vaccinated no matter where they are located," Mahjour said in a statement.

Officials at WHO and UNICEF said they are committed to working with all organizations and agencies providing humanitarian assistance to Syrians affected by the conflict. This includes vaccinating all Syrian children no matter where they are, whether in government or contested areas, or indeed outside Syria, Mahjour said.

The first priorities are to resupply and reactivate the required health infrastructure, including redeploying health workers to deliver vaccine in worst-affected areas, and moving vaccine across conflict lines where necessary and possible, Mahjour said.

Larger-scale outbreak response across the Syrian Arab Republic and neighboring countries will continue, to last for at least six to eight months depending on the area and based on evolving epidemiology, Mahjour said.