"We don't see a peaceful Syria with Assad in there", Haley said.
"We have to learn the lessons of the past and learn the lessons of what went wrong in Libya when you choose that pathway of regime change".
Lawmakers say President Donald Trump needs to work with Congress on a "long-term" Syria strategy following last week's US missile strike.
Trump said he was sending the letter as part of his efforts "to keep the Congress fully informed, consistent with the War Powers Resolution". "And I think he's making a huge mistake".
Defence Secretary Sir Michael Fallon said Russian Federation was responsible for "every civilian death" in the Syrian chemical weapons attack, claiming President Putin was to blame "by proxy" as Assad's "principal backer".
It is not clear who launched the fresh strikes on Syria's Khan Sheikhoun on Friday and Saturday, although the only aircraft that have been bombing the rebel-held region are of Russian and Syrian regime.
Medical workers and experts say victims of the the chemical release displayed symptoms consistent with a potent nerve agent, possibly Sarin.
"By proxy Russian Federation is responsible for every civilian death last week", Fallon, whose government voiced support for U.S. President Donald Trump's decision to target the Syrian air base, wrote in the Sunday Times newspaper.
Syria has been gripped by civil war since March 2011 with various terrorist groups, including Daesh (also known as ISIS or ISIL), now controlling parts of it.
After previous gas attacks in Syria which the West blamed on the Assad regime, Mr Putin made a deal with former-President Barack Obama to scrap Syria's arsenal of deadly chemical weapons.
"The intention was to take out the airfield and to remove the means of the delivery of chemical weapons".
British Defence Secretary Michael Fallon criticised Russia's support of Assad, describing the chemical attack as a war crime that happened "on their watch".
Tillerson insisted he had no concerns about possible Russian retaliation after the United States attack on the airbase.
The two leaders who talked on the telephone on Sunday said an impartial investigation should look into the chemical weapons attack on Syrian civilians last week.
"What we've seen is, you know, in our meetings this week, we were told of the evidence", she said.
The Security Council was meeting in an emergency session to discuss the US actions in Syria that Russian Federation branded a "flagrant violation of global law and an act of aggression" against Syria.