Damascus says foreign envoys are no longer welcome but signs a deal to allow humanitarian aid into the country
Syria has barred a string of US and European diplomats, saying they are "no longer welcome" in the country, but has signed an agreement to admit humanitarian aid.
Last week, western nations expelled Syrian diplomats in a co-ordinated move over the Houla massacre, in which more than 100 people were slaughtered over one weekend in a cluster of small villages.
The UN says pro-regime gunmen were believed to be responsible for at least some of the killings. President Bashar Assad has insisted his forces had nothing to do with the massacre.
The countries targeted by the expulsion order have already withdrawn their ambassadors from Damascus, but the move shows how far diplomatic ties have disintegrated over the course of the uprising, which began in March last year.
"Some countries have informed our diplomatic missions and our embassies' staff that they are unwelcome," Jihad Makdessi, a foreign ministry spokesman, said in a statement.
He said Damascus had decided to take a "reciprocal measure" against ambassadors from the US, Britain, Turkey, Switzerland, France, Italy and Spain. A number of French, German, Canadian, Bulgarian and Belgian diplomats also were affected, Makdessi said.
Meanwhile, aid workers and supplies will be allowed to enter four provinces after the Syrian government agreed to a written deal with the UN and other international organisations.
The agreement with Damascus and representatives of the government in Geneva should allow convoys with supplies and aid workers from nine UN agencies and seven other non-governmental organisations to enter Deraa, Deir el-Zour, Homs and Idlib within days, said John Ging of the UN office for the co-ordination of humanitarian affairs.
"Whether this is a breakthrough or not will be measured in the coming weeks," Ging told reporters in Geneva after emerging from a closed session to discuss the dire humanitarian situation in Syria.
Ging said the government had pledged to grant visas and clear up other bureaucratic hurdles blocking help from being delivered, and he hoped workers and supplies would enter within "days not weeks".
He said at least 1 million Syrians were in urgent need of some form of humanitarian aid, including people injured during the fighting and families who had lost jobs or homes.
More than 78,000 Syrian refugees were also being helped in Iraq, Jordan, Lebanon and Turkey, the UN refugee agency said.