Iran, which does not recognize the existence of Israel, has confirmed it supplied Palestinian fighters from Hamas and the Islamic Jihad with the technology for the rockets being fired relentlessly into Israel from Gaza since July 8.
"We will accelerate the arming of the West Bank and we reserve the right to give any response," said General Amir-Ali Hajizadeh, commander of aerial forces of Iran's elite Revolutionary Guards, in a statement on their official website sepahnews.com.
Last month, Iran's supreme leader Ayatollah Ali Khamenei urged the Islamic world to arm Palestinians to allow them to counter what he called Israel's "genocide" in Gaza.
He also said Israel was acting like a "rabid dog" and "a wild wolf", causing a human catastrophe that must be resisted.
The death toll from seven weeks of violence in Gaza rose to 2,124 on the Palestinian side on Monday. Sixty-eight Israelis have been killed, four of them civilians and the rest soldiers.
Since a ceasefire arrangement collapsed on August 19, more than 650 rockets have struck Israeli territory from Gaza and around 100 others have been shot down.
Iran's warning on Monday came a day after the Guards said they had downed an Israeli "Hermes" stealth drone above the Natanz uranium enrichment site in the centre of the country.
Natanz is Iran's main uranium enrichment site, housing more than 16,000 centrifuges. Around 3,000 more are at the Fordo plant, buried inside a mountain and hard to destroy.
Israel has often threatened to attack Iranian nuclear installations.
An Israeli spokesman told AFP in Jerusalem on Sunday after the report that the drone had been shot down that the military does "not address foreign media reports".
'Radar-evading drone' downed
Hajizadeh said at a news conference broadcast on television that the unmanned aircraft shot down was a "Hermes" stealth drone that "can evade radar".
"Pieces of the drone have been recovered intact and are being analysed," he said, adding that it had a range of 800 kilometres (500 miles).
"It was spotted by our surveillance system and shot down by a Revolutionary Guards surface-to-air missile," Hajizadeh said.
According to Hajizadeh, the drone was equipped with two cameras capable of taking high-quality images.
Footage of the recovered drone pieces was aired on Iranian television.
Iran and the P5+1 powers -- Britain, China, France, Russia, the United States and Germany -- are in negotiations to secure a nuclear deal.
They reached a six-month interim agreement under which Iran suspended part of its nuclear activities in return for a partial lifting of international sanctions.
In July that deal was extended by four months until November 24 to give the two sides more time to negotiate a final accord aimed at ending 10 years of tensions over Iran's nuclear program.
The sides remain split on how much uranium enrichment Iran should be allowed to carry out.
Washington wants Tehran to slash its program by three-quarters, but Iran wants to expand enrichment tenfold by 2021, chiefly to produce fuel for its Bushehr nuclear power plant.
Israel, a sworn enemy of Iran, opposes any agreement between the P5+1 powers and Tehran that will allow Iran to keep part of its uranium enrichment programme, saying they could use the material to make an atomic bomb.
Iran has consistently denied wanting to make nuclear weapons.