A top commander from Iran's powerful Revolutionary Guard (IRCG) has offered its support to Palestinian freedom fighters following last week's announcement by the US recognizing Jerusalem as the Israeli capital.

General Qasem Soleimani made the offer to the Palestinian commander of the al-Qassam Brigades, the armed wing of the Islamist militant group Hamas which controls the Gaza Strip, in a telephone conversation on Monday, the IRCG's website Sepahnews reported.

He said all resistance groups in the region were prepared to defend Jerusalem's al-Aqsa mosque, Islam's third-holiest site, and the location of the First and Second Temples, the most sacred site for Jews, the website wrote.

Soleimani is the commander of the IRCG's Quds Force and led Iran's fight against the terrorist group Islamic State in northern Iraq and Syria.

Iran has already harshly criticized the US decision to recognize Jerusalem as the capital of Israel and threatened consequences, with President Hassan Rowhani saying the holy city represents "more than just politics."

The US move has sparked protests around the world in support of the Palestinians, who want East Jerusalem as the capital of a future state.