TEHERAN • Iran's supreme leader Ayatollah Ali Khamenei launched a fierce attack against regional rival Saudi Arabia, saying it was being pumped "like a milking cow" by "infidel" Americans.

"These people (the Saudis) appear to believe in the Quran... but in practice they act against its teachings," Mr Khamenei said at a meeting last Saturday to mark the start of the holy month of Ramadan.

"They are close with the infidels and offer the enemy the money they should be using to improve the lives of their own people.

"But in reality there is no closeness and, as the Americans have said, they are just there to pump them for money like a milking cow, and later slaughter them," he added.

During a visit by United States President Donald Trump to Riyadh on May 21, Saudi Arabia agreed to buy US$110 billion (S$151.9 billion) of US weapons and signed investment deals worth billions more.

Sunni-led Saudi Arabia and Shi'ite-majority Iran are on opposing sides in a number of regional conflicts, including in Syria and Yemen.

Mr Trump sought to boost an anti-Iran alliance of Arab powers during his trip - but the visit was dismissed as a "show with no practical or political value" by Iran's newly re-elected President Hassan Rouhani.

Hours before Mr Khamenei's remarks, Mr Rouhani, a pragmatist who has significantly less power than the supreme leader, called for improved relations with Gulf Arab states during a telephone call with the emir, or leader, of Qatar.

"We want the rule of moderation and rationality in the relations between countries, and we believe that a political solution should be a priority," state news agency Irna quoted Mr Rouhani as telling Qatari Emir Tamim bin Hamad al-Thani.

"The countries of the region need more cooperation and consultations to resolve the crisis in the region and we are ready to cooperate in this field," Mr Rouhani told Sheikh Tamim, Irna added.

AGENCE FRANCE-PRESSE, REUTERS