The Foreign Ministry's spokesman said the continuation of Iranian military advisory services to Syria depends on the Syrian government's demand.
Hossein Jaberi Ansari made the statement in a press conference in Tehran on Monday, IRNA reported.
"Iranian advisors are in Syria upon the official request of Damascus and continuity of this presence and its level depend on the desire of the Syrian government and bilateral agreements," he said.
He was referring to the claim of US Secretary of State John Kerry on Thursday that Iran has withdrawn a "significant number" of its forces from Syria.
Asked to comment on reports of breaches of the ceasefire in Syria, Ansari expressed concern about violations by groups that are not fulfilling their promises regarding a recently-negotiated truce in the war-stricken Arab state, called "cessation of hostilities".
Under the accord accepted by Syrian government and many of its foes, which took effect on Saturday morning, fighting should cease so that aid can reach civilians and Syrian-Syrian talks are held to settle the problem.
"Terrorist groups see their interests in escalated tensions in Syria," he said. "According to field reports, terrorist forces have committed a significant number of ceasefire violations and the countries that are supporting them are well-known."
A Russian ceasefire monitoring center in Syria said on Sunday it has registered at least nine truce violations in Syria over the past 24 hours.
Ansari also touched upon recent statements by Saudi foreign Minister Adel al-Jubeir regarding the existence of "plan B" in case the political process to settle the Syrian conflict fails to produce any results.
"While just two days have passed since the cessation of hostilities, some regional players are talking about a plan B in Syria," he said.
"This will raise serious doubts over their strict adherence to decisions made in the international peace talks on Syria to have a Syrian-Syrian dialogue under the supervision of the United Nations and a cessation of hostilities."
Speaking during a news conference on Sunday, Jubeir had accused Russia and the Syrian government air force of violating the truce and said there would be a "plan B" if it became clear that the Syrian government and its allies were not serious about the truce. US Secretary of State John Kerry had also warned last Tuesday that the US has a slew of "plan B" options in case a political transition fails to work in the Arab country.
Ansari said such remarks do not seem to be positive, but hoped they are not signs of a decision by some countries to continue fueling the crisis.
"We hope they will practically prove their adherence to the outcomes of Syria talks and help the political solution for the Syrian conflict to bear fruits," he said.
