(CNN) Saudi Arabia's fresh public willingness to send ground troops into Syria is drawing ridicule from the kingdom's chief regional rival.

The commander of Iran's revolutionary guard on Saturday mocked Saudi Arabia's declaration that it is prepared to commit ground troops to fight ISIS in war-torn Syria.

"They claim they will send troops (to Syria), but I don't think they will dare do so," Maj. Gen. Ali Jafari told reporters in Tehran, according to Iran's semiofficial Fars news agency. "They have a classic army and history tells us such armies stand no chance in fighting irregular resistance forces."

"This will be like a coup de grace for them. Apparently, they see no other way but this, and if this is the case, then their fate is sealed," Jafari added, according to Fars.

Iran and Saudi Arabia, led by regimes representing opposing Islamic sects, already are bitter rivals. A years-long civil war in Syria has stoked tensions -- Iran is one of the Syrian regime's few allies, while Saudi Arabia has given financial aid and weapons to rebels.

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