Sayyed Hassan Nasrallah, leader of the militant Shiite group Hezbollah, is sending more fighters to Syria's Aleppo province, which he says has become "the greatest battle" in Syria's six-year civil war.

Watch video 02:57 Share #AleppoIsBurning: Can a Twitter trend help end the war? Send Facebook google+ Whatsapp Tumblr linkedin stumble Digg reddit Newsvine Permalink https://p.dw.com/p/1ItGW Aleppo is burning

Thousands of Sunni militant foes have recently entered Syria via the Turkish border with the aim of taking over Aleppo and its surrounding countryside, according to Nasrallah.

"We are facing a new wave...of projects of war against Syria which are being waged in northern Syria, particularly in the Aleppo region," Nasrallah said in a speech broadcast live on the group's Al Manar TV. "It was necessary for us to be in Aleppo ... and we will stay in Aleppo."

"The defense of Aleppo is the defense of the rest of Syria; it is the defense of Damascus. It is also the defense of Lebanon, and of Iraq," he said.

"We will increase our presence in Aleppo," he said. "Retreat is not permissible."

Hezbollah, which has long been backed by Iran, has been fighting alongside the Syrian government forces of President Bashar al-Assad.

Focus on Aleppo

Aleppo has become the focus of intensified fighting in the months since the Geneva peace talks collapsed and the ceasefire, orchestrated by Washington and Moscow, unraveled.

Russia stepped in last September to prop up a Syrian army that seemed overwhelmed. Russia's air campaign has decisively shifted the balance of power in the fighting, although no end to the fighting appears to be in sight.

The city of Aleppo is now divided between government forces and rebels, with the rebels holding the northern portion of the city. Russian and Syrian warplanes bombarded the main road heading north from the city, towards Turkey, effectively severing a critical supply line for the rebels.

In May Islamist insurgents, including the al Qaeda-linked Nusra Front, inflicted heavy losses on a coalition of foreign Shiite fighters including Iranian and Hezbollah members south of Aleppo.

Nasrallah acknowledged that 26 Hezbollah fighters were killed in June alone, a rare admission of the casualties the group is suffering. Several of its senior military commanders have died in the Syrian conflict, alongside hundreds of fighters.

More than 280,000 people have been killed since Syria's war erupted in 2011, and millions more have been forced to flee their homes.

Nasrallah also denied Hezbollah was facing imminent fiscal woes as a result of a US law targeting the group's finances.

bik/bk (AP, Reuters, AFP)