Aug 10 (Reuters) - Moldova cannot afford to pay for natural gas from Russia's Gazprom PAO in August and will have to hope for a deferral, the head of its state gas company was quoted as saying on Wednesday.

Moldova and Gazprom agreed a five-year contract that began on Nov. 1 last year and requires a prepayment by the 20th of each month.

"I can tell you right now that we are unable to pay," Moldovagaz Chairman Ion Ceban told the Moldovan news site NewsMaker. "We will cover July, but we cannot make the advance payment for August. That is clear."

Ceban said the small ex-Soviet republic, which over the past year has faced repeated difficulties in meeting its gas bills, hoped to reach a new agreement in the fourth quarter under which it would pay less.

"The only thing that can help us at the moment would be deferring payment of this sum until the fourth quarter," NewsMaker quoted him as saying.

Deputy Prime Minister Andrei Spinu said last week that Moldovagaz had requested deferred payment for August, but had yet to receive a reply.

Gazprom has warned Moldovagaz twice in the past year that it could halt supplies over payment delays.

(Reporting by Ronald Popeski; editing by David Ljunggren and Leslie Adler)