UNITED NATIONS (AP) -- Britain's U.N. ambassador said Thursday the Russians and Syrians must uphold the promises they made to let chemical weapons inspectors visit the site of a suspected poisonous gas attack in the Damascus suburb of Douma -- and "it should happen expeditiously."
Karen Pierce said in an interview with The Associated Press that "it's incumbent upon them more than ever to allow the team in, to escort it, to make sure it's safe, and to make sure it can do its work."
A U.N. security team that was supposed to give a green light for the inspectors to visit was shot at and subjected to a blast while touring the sites of the alleged attack in Douma on Tuesday. The visit has been put on hold and the U.N. says the security team must return to check out security measures before the fact-finding mission from the Organization for the Prohibition of Chemical Weapons can go to Douma.
First responders and activists say more than 40 people were killed in the April 7 attack, many found with foam around their mouths, a sign of suffocation. Russia said chemical weapons were not used in Douma, and recently accused rebels of staging the attack with support from Britain, an allegation that Pierce and other British officials strongly denied.
The U.S., France and Britain carried out airstrikes against suspected chemical weapons facilities belonging to the Syrian government after concluding that Syrian President Bashar Assad's forces were behind the attack, though they have not made that evidence public.
Pierce said it's "very important" that the World Health Organization, a U.N. body, "has found at least 500 cases of people reporting the symptoms of a toxic gas attack."
Douma is under the protection of Russia's military police, and with 12 days having passed since the attack, concerns are growing that evidence could fall prey to tampering or be otherwise compromised.
Pierce said "it has to be a possibility" that the Russians have tampered with evidence of the attack, "but I stress we don't yet have the facts."
And she said whether it's now too late for the inspectors to go to Douma "would depend on the extent to which the Syrians and their Russian allies have been trying to clean up sites where ... chemical weapons were suspected of being used."
The U.N. has promised a written report on Tuesday's shootings at U.N. security team, and the OPCW fact-finding mission will also produce a report on whether chemical weapons were used, and if so what kind, Pierce said.
Some analysts, including a Syrian military defector interviewed by AP, doubt the U.S., British and French airstrikes destroyed Assad's chemical weapons program and note that his conventional military capabilities are undiminished.
Asked her response to Syrians who say the airstrikes actually burnished Assad's image and made him look like a survivor against "Western aggression," Pierce said: "I don't think it burnished his image at all."
"I think it's exposed him as a suspected war criminal who gasses and attacks and bombs his own people with illegal weapons," she said. "That, I think, is the most important point here."
Pierce and the other ambassadors on the U.N. Security Council are heading to Sweden for their annual retreat with Secretary-General Antonio Gutteres this weekend, where the council's deep divisions and failure to end the seven-year Syrian conflict are expected to be a key issue.
Guterres wants to relaunch the Geneva political process aimed at restoring peace to the country.
Pierce said the United Kingdom can work with Russia in the Security Council on issues like Somalia and Colombia which were on its agenda this week, "but on the biggest conflict issue of the day, Syria, they are proving very, very difficult to work with."
"We would much rather be able to do things in cooperation with them, but there has to be a doubt as to the direction of Russian policy," she said. "There has to be a doubt as to whether they still believe only a political solution can bring this conflict to an end."