Syrian and Russian officials say the Army plans major operations to retake the eastern cities of Dayr al-Zawr and Raqqah and Aleppo from Takiri militant groups.
The Syrian daily al-Watan, citing political and military officials, said the Army and its allies are gearing up for a "decisive battle" to liberate Aleppo.
"The time has come to liberate Aleppo from the contamination of terrorists," it cited officials as saying.
The report said the Army had sent letters to terrorists, warning them against using civilians in Syria's second city as human shields.
'Regime of calm' in Damascus and Latakia
The report came as the Syrian army declared a temporary truce for the capital, Damascus, and its suburbs, and the coastal province of Latakia.
The announcement was read on Syrian state TV on Friday, with the army saying the ceasefire will go into effect at 1 a.m. on Saturday.
The military statement said the ceasefire will last 24 hours in Damascus and its suburbs and three days in Latakia.
Alexei Borodavkin, Russia’s ambassador to the UN office in Geneva, said the Syrian army would soon launch the offensive in Dayr al-Zawr and Raqqah with the support of the Russian air cover.
“In line with UNSC [UN Security Council] Resolution 2254, the ceasefire regime in Syria does not apply to Daesh, al-Nusra Front and other terrorist groups," Borodavkin said.
"As a result of operations by the Syrian armed forces with the support of Russian combat aircraft…offensive operations are being planned in the direction of Day al-Zawr and Raqqah,” he added.
Russia began airstrikes on Takfiri targets in late September on the request of the Syrian government.
Borodavkin accused the foreign-backed opposition groups of “deliberately” violating an existing ceasefire, saying arms flow into Syria continued through the Turkish border.
“We are constantly talking about the need to block the Turkish-Syrian border through which terrorist group fighters flow and weapons, military equipment and ammunition are smuggled," he said.
"It is necessary to firmly curb this flow in order to strengthen the ceasefire regime,” Borodavkin added.
UN-brokered peace talks were brought to a halt after the foreign-backed opposition walked out of the discussions and militants declared a new war against the Syrian government.
On Friday, the so-called Syrian Observatory for Human Rights said over 200 people had been killed during the past seven days of intensified violence in Aleppo.
Russia and Syria have dismissed accusations that their warplanes had targeted a hospital in Aleppo, with Moscow suggesting the US-led coalition was responsible for the incident.
In a statement, the Russian Defense Ministry said that Moscow had conducted no airstrikes in Aleppo in recent days.
'War crimes' in Aleppo
Syrian Information Minister Omran al-Zoubi said terrorist attacks targeting Aleppo for days now amount to war crimes.
“What has happened in Aleppo over the past days of terrorist rocket and sniper shooting attacks is considered a real war crime that needs no further proof or evidence,” he said.
“There can no longer be room for patience or silence on these crimes that are targeting the Syrians indiscriminately,” he added.
Zoubi also accused Saudi Arabia, Turkey and "other terrorism-sponsoring forces" of fomenting crimes in Aleppo. He said terrorists have used internationally-banned weapons against locals in the city.
US senator urges support for Damascus
On Thursday, a US state senator held a meeting with Syrian President Bashar al-Assad in Damascus, calling for more support for the government.
Contracting the official US stance on the conflict in Syria, Republican State Senator Richard Black voiced strong criticism against the Syrian opposition.
He described the foreign-backed opposition as "a group of terrorists fighting against the legitimate government and the Syrian people."
The Syrian official news agency SANA said Black arrived in Syrian for a three-day visit, the first visit of an American senator in Syria since 2012.
"What is happening in Syria is terror. The issue is that terrorists are fighting against the Syrian people and their legitimate government," he said upon arrival.
"There is no such thing as 'moderate opposition' in this country," he said.
"Many people misunderstand the situation in Syria, and refuse to believe that all the groups fighting against the Syrian regime are terror groups," Black added.
"I know that the Syrian President Bashar Assad wants to have a modern state, where people would enjoy freedom of religion," he said.
Black said Assad is a legitimate president, since "he was legally elected in 2014 elections."
Expressing wonder over the Saudi intervention in Syria, the senator asked: "How can states like Saudi Arabia, where elections have never taken place, push for elections in Syria and demand that it changes its constitution?"
In his meeting with the Syrian parliament speaker Mohammad Jihad Lahham, Black said: "The conflict in Syria affects the future of our civilization.”
“Hence, if Syria loses this war, our civilization specifically and the humanity in general will suffer dangerous repercussions.”
Black said that when he gets back to the US, he will warn the American administration "not to provide military aid to the terrorists and mercenaries that are fighting in Syria."
In an interview in March 2015, Black stated: "if Assad falls, ISIS (Daesh) will march to Europe."