U.S. President Donald Trump has warned Syrian President Bashar al-Assad and his allies Iran and Russia not to "recklessly attack" Syria's last opposition-held province, Idlib, warning that hundreds of thousands of people could be killed.
"The Russians and Iranians would be making a grave humanitarian mistake to take part in this potential human tragedy. Hundreds of thousands of people could be killed. Don’t let that happen!" Trump wrote on Twitter late on September 3.
But Moscow on September 4 rejected the warning, with Kremlin spokesman Dmitry Peskov saying Trump's tweet demonstrated a limited approach toward the situation in Idlib Province.
"Just to speak out with some warnings, without taking into account the very dangerous, negative potential for the whole situation in Syria, is probably not a full, comprehensive approach," Peskov said.
"The Idlib situation continues to make us feel strongly concerned in Moscow, Damascus, Ankara, and Tehran," Peskov said, adding that the presence of militants in the province was undermining the Syrian peace process and making the region a base for attacks against Russian forces in Syria. "This is another hotbed of terrorism."
"There is no doubt that the issue should be dealt with," Peskov said. "We know that Syrian government forces are preparing to solve this problem."
Peskov also said the situation in and around Idlib Province will be a main item on the agenda when President Vladimir Putin meets in Tehran on September 7 with the leaders Iran and Turkey.
Syria has been preparing for a major assault on the province bordering Turkey, which is the last major enclave held by opposition fighters battling Assad and the Russian and Iranian forces that have played a critical role in backing him in the seven-year war.
Thousands of Syrian government troops and allied fighters have been massing in areas surrounding the province.
Meanwhile, monitors from the London-based Syrian Observatory for Human Rights said on September 4 that Russian warplanes, in support of Assad's forces, had resumed air strikes in Idlib after a 22-day break.
Idlib is home to an estimated 3 million civilians and the United Nations has warned that some 800,000 people could be forced from their homes by any major government offensive. The war has already killed more than 400,000 people and displaced millions.
As signs of an impending assault have mounted, Washington and its allies have sought to put a spotlight on both Russia and Iran for backing Assad and his sometimes brutal tactics, including the alleged use of chemical weapons.
"All eyes on the actions of Assad, Russia, and Iran in Idlib. #NoChemicalWeapons," U.S. Ambassador of the United Nations Nikki Haley, wrote on Twitter minutes after Trump's tweet.
Their comments came after Iranian Foreign Minister Mohammad Javad Zarif on September 3 called for militants to be "cleaned out" of Idlib on a visit to Damascus ahead of an upcoming summit between the leaders of Iran, Russia, and Turkey in Tehran on September 7 to discuss Idlib.
"In order to start the peace process as well as the return of refugees and to allow the start of the reconstruction phase in Syria, the remaining terrorists in parts of Idlib must be cleaned out," Zarif said.
Iran, Russia, and Syria often describe all their armed opponents as "terrorists."
In the case of Idlib, an estimated 10,000 fighters with the Al-Qaeda-linked Hayat Tahrir al-Sham group are believed to be the dominant force among rebels in the province, and the Russian military has made a distinction between those forces and what it has described as more moderate "opposition" groups allied with Turkey, its negotiating partner.
The Russian state-run news agency TASS quoted Russian Deputy Foreign Minister Oleg Syromolotov as saying on September 3 that "no one wants active hostilities that can kill civilians" in Idlib and "efforts are being taken to find a solution, first of all, to separate the opposition from [Hayat Tahrir al-Sham]. This is probably the main thing. If it is done, a solution will be found."
Ahead of the Idlib assault, Turkey has stepped up efforts to negotiate with Russia and Iran to separate out and protect the rebel groups it backs, media have reported. Ankara also has stationed some troops in the province as part of an observation mission.
Zarif's visit to Syria comes a week after Iran's defense minister traveled to Damascus and signed a defense cooperation agreement, defying U.S. calls for Iran to withdraw its military advisers and fighters from the war-torn country.