As the United States consults with allies about a possible military response to a suspected chemical weapons attack in Syria, Russia said Wednesday that all parties involved should refrain from actions that could destabilize the fragile situation in the region.
Russia is an ally of Syrian President Bashar al-Assad and has fought in support of his government in the conflict since 2015. The United States has backed rebel groups in Syria and blames Assad's forces for the attack in eastern Ghouta on Saturday that killed at least 40 people.
Both Syria and Russia have denied the allegations.
U.S. President Donald Trump has warned those responsible will pay a "big price," and he has spoken repeatedly with his British and French counterparts about a possible response to the attack.
"We are looking for a coordinated response, whatever that response might be," State Department spokesman Heather Nauert said Tuesday.
French President Emmanuel Macron said a decision would be made "in the coming days," and that any airstrikes would target the Syrian government's chemical facilities.
Australian Foreign Minister Julie Bishop added her country's support Wednesday for any action that is "targeted, calibrated and proportionate."
In addition to blaming Syria, Trump has further blamed Assad's backers in Iran and Russia for the eastern Ghouta attack. A global chemical weapons watchdog on Tuesday said it will send a team to investigate the incident.
WATCH: US response to Syria
The World Health Organization said Wednesday that according to reports from its partners, 500 people who sought treatment Saturday showed signs and symptoms of toxic chemical exposure. The WHO expressed outrage at the suspected use of chemical weapons and demanded immediate access to the area to provide care.
At the U.N. Security Council on Tuesday, Russia vetoed a U.S.-drafted plan that would have set up a commission to investigate and assign blame for the chemical weapons attack.
As the U.S. mulled its response, the White House said Trump canceled a trip to Latin America, which was to begin Friday, so that he could "oversee the American response to Syria." Defense Secretary Jim Mattis also called off domestic travel plans.
White House officials refused to say whether the response included the possibility of prolonged U.S. military action in Syria or would amount to more than just a "one-off" airstrike.
"The president and his national security team thought it was best that he stay in the United States while all these developments are taking place," said press secretary Sarah Huckabee Sanders.
The U.S. is already deeply involved in the seven-year-old Syrian civil war. Over 2,000 U.S. troops are in Syria. A U.S.-led coalition has launched thousands of airstrikes there, mostly against Islamic State and other extremist rebels.
Almost exactly a year ago, the U.S. launched 59 Tomahawk cruise missiles at a Syrian government airbase in retaliation for another chemical weapons attack.
But too intense a response to the latest attack risks escalating the Syrian civil war and exacerbating military tensions between major world powers that all have proxies on the ground, according to analysts.
"There's no easy answer here," retired Admiral Michael Mullen told VOA contributor Greta van Susteren on Tuesday. "It's delicate, it's dangerous. I worry that it could expand fairly rapidly."
Trump has said he would like to pull U.S. troops from Syria, citing progress in fighting Islamic State. Many in the U.S. foreign policy community, including Mullen, disagree with such a withdrawal.
"The couple thousand troops that we have there are a stabilizing force," Mullen said. "I think [they] need to be there until it's very obvious that they shouldn't be there or that they don't need to be there anymore."
It's unclear what an expanded U.S. military campaign in Syria would look like, including what the targets would be or which U.S. allies would be involved.
Options appear few
But the U.S. appears incapable of substantially altering the direction of the conflict, said Andreas Krieg, a Middle East specialist at King's College London.
"Unlike 2013, the West no longer has the leverage to shape or determine outcomes in Syria's civil war," Krieg said. "Punitive air or missile strikes will have limited effect, and neither deter Assad nor deny his ability to use chemical weapons again."
Trump has for years warned of the dangers of the U.S. becoming too involved in Syria.
"What will we get for bombing Syria besides more debt and a possible long term conflict?" Trump said in a 2013 tweet. "[Former President Barack] Obama needs Congressional approval."
More recently, Trump has changed course. In a tweet this week, Trump said that if Obama had pursued more vigorous military action in Syria, "Animal Assad would have been history."
Daniel Davis, a retired U.S. Army lieutenant colonel who is now a senior fellow and military expert at the Washington-based think tank Defense Priorities, said he thought Trump should follow his earlier inclination.
"This would profoundly worsen our situation here," Davis said. "We cannot take that kind of risk of escalating a contained civil war. We've also got the possibility of armed conflict with Russia, which isn't in our interest at all."
Russia has warned of "grave repercussions" if the U.S. strikes Assad.