DAMASCUS, Aug. 26 (CGTN) -- Syrian President Bashar al-Assad on Sunday underscored the importance of placing long-term cooperation plans between Iran and Syria in the face of the challenges, according to the state news agency SANA.

Assad made the remarks during his meeting with visiting Iranian Defense Minister Amir Hatami, who arrived in Syria on Sunday to hold meetings with top Syrian officials to discuss various issues such as expanding military and defense cooperation.

During the meeting, Assad slammed the policies of the US and its allies, saying the US wants to prolong the Syrian war by supporting the terrorist groups and via adopting the policy of threats.

The US threats increase every time the Syrian army launch an offensive against the terror groups, Assad said, referring to the recent threats of the United States, Britain and France, which threaten to use force if a chemical weapon attack was carried out by the Syrian army.

The three powers' stance comes as the army is preparing to launch a wide-scale offensive on Idlib province, the last major rebel stronghold in northwestern Syria.

Damascus slammed the warnings as threats, saying these powers are pushing their allies of the rebels to use chemical weapons to frame the government forces to justify a foreign strike on Syria.

Assad said the US stance proves "the rightness of the policies of the anti-terror axis (Iran, Syria, and Russia) and the need to strengthen such axis in the face of the sabotaging US approach, which undermines the international stability."

Hatami, meanwhile, stressed his country's supportive stance in preserving the independence and unity of Syria far from foreign interventions.

He stressed that Iran will continue to work to support Syria no matter how far the threats and pressure go from the countries that support the terror groups.

The visit of the Iranian minister comes at a time when the Syrian army has achieved major progress with the help of Iran and Russia as well as Hezbollah.