Damascus, Syria (CNN) -- Former UK Prime Minister Tony Blair called the West to military action Tuesday over reports of the use of chemical weapons in Syria.
"Western policy is at a crossroads: commentary or action; shaping events or reacting to them," he wrote in an essay published in the Times of London.
"People wince at the thought of intervention. But contemplate the future consequence of inaction and shudder: Syria mired in carnage between the brutality of Assad and various affiliates of al-Qaeda. ..."
The office of the current prime minister, David Cameron, said Tuesday that the country's military was making "contingency plans" with regards to Syria.
n Washington, U.S. Secretary of State John Kerry on Monday called the use of chemical weapons a "moral obscenity" that could not go unanswered, and he said Syrian actions are "not the behavior of a government that has nothing to hide."
Kerry stopped short of directly accusing President Bashar al-Assad's government of a massacre. But he said, "We know that the Syrian regime maintains custody of these chemical weapons. We know that the Syrian regime has the capacity to do this with rockets. We know that the regime has been determined to clear the opposition from those very places where the attacks took place."
Meanwhile, he said that Syria was "systemically destroying evidence" of last week's attack by continuing to shell the area and that the danger a team of U.N. inspectors faced Monday "only further weakens the regime's credibility."
The Obama administration is now weighing how to respond in talks with U.S. allies and members of Congress, he said.
The use of a large amount of chemical weapons would cross a "red line" and threaten U.S. interests in the region, Obama announced last year. It may give the United States cause to take action.
Russia objects, again
The Russian foreign ministry on Tuesday accused the United States of trying to "create artificial groundless excuses for military intervention" in Syria.
In a statement, the ministry complained that Washington was attempting to bypass the U.N. Security Council to take action on the reported chemical attacks.
Russia is an ally of Syria's president and has a permanent seat on the council. It is capable of blocking measures against his government that are proposed to the U.N. body.
Moscow also bemoaned the postponement by the United States of a meeting that was scheduled for Wednesday in the Hague, where top diplomats from both countries had planned to discuss the war in Syria.
Russia's foreign minister, Sergey Lavrov has said that there is no proof yet that the Syrian government was involved in last week's reported attack. His office has compared the Western allegations against Syria to the claims that Iraq was hoarding weapons of mass destruction before the U.S. invasion in 2003 -- claims that fell apart once American troops began searching for them.
Middle East analyst Richard Haass told CNN's "The Lead" that Kerry's comments "went far out on a limb" and indicate that a U.S. strike on Syria was in the works, with or without U.N. Security Council backing. Haass, the president of the Council on Foreign Relations, said military action was needed "to underscore the principle, the norm, the taboo that these weapons ought to have."
"No one, Syria or anybody else, now and forevermore, should be able to use such weapons, much less biological or nuclear weapons, with impunity," he said. But he said Washington should limit its intervention in the conflict, "so we don't get enmeshed in what I think could become a quagmire."
U.N. inspections delayed
U.N. inspectors had been expected Tuesday to examine for a second day sites of reported chemical weapons attacks around Damascus. On Monday, U.N. experts visited the town of Moadamiyet al-Sham.
But Syrian Foreign Minister Walid Moallem said that Tuesday's planned trip to the outskirts of Damascus had been delayed until Wednesday because of security concerns.
Moallem denied Tuesday that the government was delaying the inspections, saying instead it is rebel forces that are hindering the inquiry. He also denied that Syria's army removed chemical weapons residues from the scene, saying the area is held by rebel forces.
Government and opposition forces have accused each other of unleashing poison gas last week in a number of towns in the region of Ghouta. Syria's opposition said that as many as 1,300 people were killed.
Before the inspection, unidentified snipers shot multiple times at one of their vehicles, and there was an explosion near the inspection site, the United Nations said. There were no reports of injuries.
Speaking from Seoul, South Korea, U.N. Secretary-General Ban Ki-moon said he has directed the group to register a "strong complaint" to government and opposition forces to make sure the team's safety is guaranteed.
Ban said inspectors visited hospitals, interviewed witnesses, survivors and doctors and collected some samples.
Videos posted on social media by Syrian activists showed inspectors who appeared to be examining the area accompanied by doctors.
The Syrian government would not let U.N. inspectors approach the site for days, and the team feared that the chemical evidence may have dissipated.
Missile strikes on Syria likely response to chemical attack
Al-Assad: It wasn't us
The Pentagon has sent four warships armed with cruise missiles to the region, and Obama will be presented with final options regarding actions against Syria in the next few days, a senior administration official said Monday.
But as U.S. muscle plows the waters of the eastern Mediterranean Sea, al-Assad on Monday repeated his government's denial that his army had anything to do with the use of poison gas.
"The area of the claimed attack is in contiguity with the Syrian army positions, so how is it possible that any country would use chemical weapons in an area where its own forces are located?" he asked in an interview with Russian newspaper Izvestia.
Al-Assad accused the United States, Britain and France of exploiting the incident by trying to verify rebel allegations instead of verifying facts.
Opposition members say rockets with chemical payloads were among the ordnance government troops unleashed at the rebel stronghold of Ghouta early Wednesday. More than 1,300 people died, most of them by gas, according to opposition spokesman Khaled al-Saleh.
The opposition backed up the allegations with gruesome video of rows of dead bodies, including women and children. They had no visible wounds, and some appeared to be bloated.
But according to Syrian state-run television's depiction of events, government forces came into contact with a gas attack on Saturday in Jobar, on the edge of Damascus. Several of the soldiers were "suffocating" from exposure to gases as they entered the city, according to state TV.
"It is believed that the terrorists have used chemical weapons in the area," Syrian TV reported, citing an anonymous source. The government uses the term "terrorists" to describe rebel forces.
Broadcast video showed a room containing gas masks, gas canisters and other paraphernalia that could be used in a gas attack. The army said it uncovered the cache in a storage facility in the area.
CNN could not independently confirm the authenticity of video shown by the government or rebels.