Syria's state-run news agency says the country's foreign minister has told UN chief Ban Ki-moon that humanitarian aid won't be allowed into an embattled rebel-held Syrian town until the fighting there is over.

The SANA news agency say UN chief Ban Ki-moon called Foreign Minister Walid al-Moallem on Sunday to express concern over the situation in the town of Qusair.

The regime launched an offensive against Qusair three weeks ago and has gained ground, though rebels have defended some positions.

The Syrian regime launched an offensive on Qusair three weeks ago.The Syrian regime launched an offensive on Qusair three weeks ago. (Ugarit News/Associated Press)

On Saturday, the International Committee of the Red Cross and UN humanitarian agencies called for a cease-fire, expressing alarm over the fate of thousands of civilians believed to be trapped there, including many wounded.

SANA says al-Moallem told Ban the Red Cross and others will be able to enter Qusair "after the end of military operations there."

On Sunday, UN chief Ban Ki-moon called Syrian Foreign Minister Walid al-Moallem to express concern over the situation in Qusair, according to Syria's state-run news agency SANA.

However, al-Moallem told the UN chief that the Red Cross and other aid agencies will only be able to enter Qusair "after the end of military operations there," SANA said.

Fighting has already dragged on for three weeks and so far neither side has been able to deliver a decisive blow. Syrian regime troops and Hezbollah fighters launched the offensive against Qusair in mid-May and gained ground, but rebels were able to defend some positions.

Meanwhile, low-flying Israeli warplanes violated Lebanese airspace, overflying the capital Beirut, the eastern Bekaa Valley and the city of Baalbek.

Lebanese President Michel Suleiman said Lebanon would lodge a complaint with the UN to protest Israel's "extensive" violations of Lebanese airspace. Israeli warplanes regularly enter Lebanese airspace.

There was no immediate comment from Israel.