The U.N.'s health agency's statement Wednesday said the joint resolution by nations in WHO's Eastern Mediterranean region have called on Pakistan to urgently vaccinate all of its children to prevent the virus from spreading internationally.
Pakistan also approved the resolution, which the WHO says includes Afghanistan, Bahrain, Djibouti, Egypt, Iran, Iraq, Jordan, Kuwait, Lebanon, Libya, Morocco, Oman, Qatar, Saudi Arabia, Somalia, Sudan, Syria, Tunisia, the United Arab Emirates, and Yemen.
WHO officials said earlier this week that the polio virus has now been confirmed in 13 of 22 children who became paralyzed in a northern Syrian province.
Seven countries and territories are holding mass polio vaccination campaigns targeting 22 million children, according to the WHO.
The health agency says the Syria outbreak comes from a strain that originated in Pakistan, where, along with Afghanistan and Nigeria, it is endemic -- and has been spreading across the Middle East.
It says the virus has been detected in Egypt, and closely related strains of Pakistani origin turned up in sewage samples in Israel, the West Bank and Gaza Strip, but higher immunization rates in those places have helped keep the virus in check.
A research letter published Nov. 8 in The Lancet suggests a polio outbreak in the Middle East could have far-reaching implications in neighboring Israel and Europe.
The letter's authors contended that some countries have low vaccination coverage rates, including Bosnia and Herzegovina, Ukraine, and Austria. If polio were to be introduced to these regions from refugees fleeing Syria to Europe, herd immunity might not be enough to prevent an outbreak, they said.