BRASILIA - Russian President Vladimir Putin said on Thursday that Saudi Arabia was taking a tough stance on the output deal between OPEC and its allies because of Saudi Aramco's initial public offering, but that Moscow respected Riyadh's interests.

Speaking to reporters in Brazil at a summit for BRICS countries, Putin said Moscow should continue to work with OPEC and that cooperation should not only be on oil production cuts.

OPEC, Russia and other oil producers have since Jan. 1 implemented a deal to cut output by 1.2 million barrels per day. In July, the alliance renewed their pact until March 2020. They are set to meet for policy talks on Dec. 5-6.

"We have really constructive dialogue with OPEC," Putin said. "We understand that the tough stance, including from our friends from Saudi Arabia, is linked to the Saudi Aramco IPO. Everybody understands this. It's an open secret."

Saudi Arabia's giant state oil company kick-started its IPO earlier this month and is set to start a share sale on Nov. 17 in an initial public offering (IPO) that may raise between $20 billion and $40 billion.

(Reporting by Vladimir Soldatkin and Gabrielle Tétrault-Farber; writing by Tom Balmforth; editing by Giles Elgood)