Russia has revealed it warned the US about "red lines" it should not cross before it launched airstrikes on Syria.
Foreign minister Sergei Lavrov is reported to have said that officials in Washington were contacted before last weekend's strikes by the US, UK and France.
Mr Lavrov said: "There were military leadership contacts, between generals, between our representatives and the coalition leadership.
"They were informed about where our red lines are, including red lines on the ground, geographically.
"The results show that they did not cross these red lines."
Some 105 missiles were launched in response to a suspected chemical attack in the Syrian city of Douma on 7 April that killed more than 40 people.
The Kremlin had threatened retaliatory action if strikes were launched - but it now appears there was at least some level of cooperation.
Russia, a key ally of Syria, has denied that any chemical attack took place.
International inspectors from the Organisation for the Prohibition of Chemical Weapons (OPCW) arrived in Damascus almost a week ago but are still waiting to visit the site of the suspected attack.
Mr Lavrov said the missile strikes have removed a "moral obligation" that had been preventing it from delivering a cache of S-300 missiles to the Syrian regime.
"Now, we have no moral obligations," he said.
"We had the moral obligations, we had promised not to do it some 10 years ago, I think, upon the request of our known partners.
"We took into consideration their claim that this could destabilise the situation - even though it is purely defensive.
"Now we don't have this moral obligation any longer."
Military analysts say the S-300 surface-to-air missile system would boost Russia's ability to control airspace in Syria, where Moscow's forces support the government of President Bashar al Assad, and could be aimed at deterring tougher US action.
The state news agency RIA also reported Mr Lavrov saying he was convinced Vladimir Putin and Donald Trump would not allow an armed confrontation between their countries.
He said: "I am 100% sure that the military will not allow this to happen and neither President Putin nor President Trump will allow this to happen.
"They are the leaders who were elected by their peoples and they are responsible for peace and calm."
It comes as President Trump invited his Russian counterpart to the US during a phone call, and said he would be glad to see Mr Putin in the White House, according the Russian foreign ministry.
Mr Lavrov is reported to have said President Trump returned to the subject of an invitation a few times during a phone call with President Putin.
He told President Putin he would be happy to make a reciprocal visit to Russia, the RIA news agency quoted Mr Lavrov as saying.