Inspectors from an international agency sent to collect air, water and ground samples from the site of a suspected poison gas attack in Syria this month were blocked Monday by Russian and Syrian forces for security reasons, the watchdog group's director said.
The delay in obtaining independent confirmation of suspected chemical weapons use came as the White House postponed plans to add sanctions on Russia for what the Trump administration said was its support of Syrian President Bashar Assad's poison gas program.
Nikki Haley, the U.S. ambassador to the United Nations, had said Sunday that new sanctions would be announced Monday, but the White House pulled back. "We are considering additional sanctions on Russia, and a decision will be made in the near future," White House Press Secretary Sarah Huckabee Sanders told reporters.
She did not say if Haley had misspoken or if President Trump had changed his mind to avoid worsening relations with Moscow. The Trump administration has taken an increasingly tough line on Russia even as the president has been reluctant to criticize President Vladimir Putin for his government's meddling in the 2016 U.S. election and other actions.
The confusion emerged as nine inspectors from the Organization for the Prohibition of Chemical Weapons waited in Damascus for permission to visit Duma, a suburb east of the Syrian capital that was attacked on April 7.
U.S. officials say Assad's forces killed more than 40 people, including children, with chlorine gas and possibly sarin, a banned nerve agent. But U.S. intelligence has been unable to collect ironclad evidence of which chemical agents were used.
U.S. and British officials have accused Russian units in Duma of trying to hide or tamper with evidence of the chemical attack, a claim Moscow denies.
Stephane Dujarric, spokesman for United Nations Secretary-General Antonio Guterres, said in New York that the OPCW team had all "necessary clearances" to collect samples in Duma.
But Ahmet Uzumcu, director general of the OPCW, which is based in The Hague, said in a report to member states that Syrian and Russian officials had contended "there were still pending security issues to be worked out before any deployment could take place."
Uzumcu expressed hope the inspectors could visit Duma "as soon as possible."
U.S., French and British forces fired more than 100 missiles at three targets in Syria early Saturday in retaliation for the Duma attack. The three facilities developed, produced or stored chlorine or sarin, Pentagon officials said, and all appeared heavily damaged.
Syria has denied stockpiling or using chemical weapons, which are illegal under international law. Russia, which backs Assad, also has denied that a chemical attack occurred, and noted that it initially invited the weapons inspectors to Duma.
Russian Foreign Minister Sergei Lavrov on Monday repeated his government's assertions that no chemical attack took place and said photographs and videos that showed people choking to death and other symptoms of chemical poisoning were "staged."
Speaking to the BBC, Lavrov angrily condemned Washington's attempts to blame and punish Russia, saying relations between the two countries were worse than during the Cold War.
The latest evidence came with a joint warning Monday from the Department of Homeland Security, the FBI and the British government. They said a new wave of Russian "cyberespionage and aggression" had targeted governments and private companies through digital attacks on cyberinfrastructure like routers and firewalls.
A British government spokesman said the joint warning sent a "clear message to Russia: We know what you are doing and you will not succeed."