The Syrian government set conditions on Thursday for any international inquiry into a suspected chemical attack that killed scores of people, saying it must not be "politicized" and should set out from Damascus and not Turkey.
Foreign Minister Walid al-Moualem said Syria's past experience with international inquiries had not been encouraging. The government would only decide on the idea once its concerns were addressed, he said.
Mr. Moualem also reiterated the government's strong denial that it was behind the attack on Tuesday in Khan Sheikhoun in the northwestern province of Idlib, an area mostly controlled by rebel groups at the border with Turkey.
President Trump on Wednesday said President Bashar al-Assad's government had gone "beyond a red line" and said his attitude towards Syria and Assad had changed. But he gave no indication of how he would respond.
Moualem did not directly respond to questions about Mr. Trump's comments. But he said he recognized "the gravity" of recent statements by the United States, and cited speculation US comments may have been a means of exercising diplomatic pressure at the United Nations.
Moualem, speaking at a news conference in Damascus, said the Syrian government's Russian allies had put forward ideas for the formation of a "non-politicized commission of inquiry."
"It must not be politicized, it must leave from Damascus and not Turkey. We have numerous questions about this subject. When we are certain these questions are addressed with convincing answers, we will give you our response," he said.
Western states have accused the Syrian government of carrying out the chemical attack on Tuesday that killed at least 70 people including at least 20 children. Russia has said the deaths were caused by a gas leak from a depot where rebel groups were storing chemical weapons, after a Syrian air strike.
Moualem said a Syrian air strike had hit a store where the Nusra Front was storing chemical weapons. The Nusra Front is a jihadist group that now operates as part of an alliance called Tahrir al-Sham. He said the Nusra Front and Islamic State had both been storing chemical weapons in urban areas of Syria.
Rebels have denied that there were any military positions in the area targeted in Tuesday's air strike.
Moualem also said the first Syrian air strike carried out in the area took place at 11:30 a.m., some five hours after an air raid observer in Khan Sheikhoun reported that a lone Syrian jet had dropped at least four bombs there, including one that released a cloud of white smoke.
"I confirm to you once again that the Syrian Arab Army has not and will not use this type of weapon against our people and our children, and not even against the terrorists who kill our people," Moualem said.
Moualem also said he saw a basis for an eventual "understanding" with Kurdish groups that have established control over wide areas of northern Syria, where they are fighting Islamic State with US support.
He said the Kurds wanted to remain part of Syria. "I am confident we will reach an understanding with them after accomplishing the struggle against terrorism," he said.
The head of the main Syrian Kurdish militia, the YPG, last month indicated it was ready to reach an accommodation with the Syrian government once Kurdish rights are secured. The dominant Syrian Kurdish parties say they want to maintain a form of local autonomy in an eventual settlement to the Syrian war.