"It is regrettable that such language should come from the ambassador of a great power who is supposed to show more commitment to the norms of international relations," Syrian Information Minister Mahdi Dakhlallah said on Monday.
The US ambassador to Iraq, Zalmay Khalilzad, fired a strong warning to Syria earlier during the day over help that Washington accuses the Damascus government of giving to radical groups in Iraq.
"Our patience is running out with Syria," Khalilzad said in Washington. When asked how the US could respond, he said "all options are on the table", including military.
"I would not like to elaborate more, they should understand what I mean," Khalilzad said.
Dakhlallah retorted: "There is a threat of aggression there, and a style which is reminiscent of colonial eras and cold and hot wars.
US envoy to Iraq Khalilzad said
time was running out for Syria
"Moreover, there are old, groundless accusations relating to the Iraqi-Syrian borders."
Dakhlallah said: "Syria has exerted efforts almost beyond its capacity as a small and developing country to protect the border because Iraq's stability is a Syrian concern, not just an Iraqi concern. Stability is indivisible and dangers most often come from two directions.
"In any event, we have got used to this language from the United States. It represents a clear escalation in a chain of successive pressures on Syria," he added.
Khalilzad said the US believes that Iraqi Sunnis are refusing to agree to a proposed constitution because of threats from Sunni extremists who have infiltrated into Iraq from Syria, where they have training camps.
No proof given
"Syria has to decide what price it's willing to pay in making Iraq success difficult. And time is running out for Damascus to decide on this issue," Khalilzad warned.
The US diplomat offered no proof of claims of Syrian interference, which he called "blatant".
Syria has repeatedly rejected charges that it allows anti-US fighters to cross its border into Iraq.
Syrian authorities face intense
pressure to meet US demands
Speaking to Aljazeera, Emad Fawzi Shuaibi, a Syrian strategic-affairs analyst, said on Tuesday the US allegations are part of a media broadside targeting Syria at this particular point of time.
"The accusations are an attempt to place Syria between the US hammer, in the context of al-Hariri case investigator's visit, and the anvil of the Iraqi issue," he said.
"It is worth noting that the US commissioner and the military attache were the only two diplomats absent from the tour the Syrians organised to show Arab and Western diplomats what they have done on the Syrian-Iraqi border," Shuaibi said.
"Syria has set up 567 checkpoints near the border and deployed 10,000 soldiers in the area," he explained.
Shuaibi believes the US is determined not to see for itself the steps Damascus has taken to better police the Syrian side of the border with Iraq.
"This media broadside is a response to the prompt action taken by Syrian officials on the infiltration issue," he said. "That is why the US has threatened to exercise the military option."
Furthermore, Shuaibi told Aljazeera he was certain the US threats were linked to UN investigator Detlev Mehlis's visit to Damascus.
Heavy fighting is going on along
the Syrian-Iraqi border
"The entire situation is tied to the US demands, which aim to weaken Syria's position and force it to hold talks with Israel on the basis of peace for surrender," he said.
Shuaibi said the US will place conditions on Syria to compel it to throw Palestinian leaders out of the country and abandon the Palestinian cause in return for nothing.
"They will also force Syria to abandon Lebanon to rule by Israel and other embassies," he added.
"But Syrians have defied the conditions being forced on them and retaliated by receiving Palestinian resistance leaders, whose cause they refuse to abandon," Shuaibi said.