Arsenal rejected two bids for Fabregas last year, and they have already turned down a further offer this summer, but Guardiola has now confirmed the reports that the Gunners are now willing to talk over their captain.
"Last year we were interested in Cesc but Arsenal did not make him available," he told a press conference. "This year Arsenal have agreed to negotiate and we're working on it. Prices in the market are what they are right now, but I hope that everything can be resolved."
He added: "Everything we have done has been with the permission of Arsenal and Mr Wenger knows that."
However, Guardiola also revealed that Fabregas is not the club's number one priority this summer and suggested he would be happy to wait another year to complete the deal.
"Between a midfielder and a forward, our priority is a forward," he said, "but there's money for two players."
He added: "There is money available to sign the player and until the last day [of the transfer window] we will try to sign him, but I'm the first to understand that sometimes these things cannot happen.
"Cesc will make us better, we're interested, but if it's not to be then maybe we will complete the deal next year and use the money for something else."
There have been suggestions Fabregas could force Arsenal's hand by refusing to play for the club or demanding a transfer, but Guardiola said: "I don't like it when players go on strike.
"Cesc has to do what Arsenal ask. If he didn't go on the club's pre-season tour to Asia, it's because he's injured. He belongs to Arsenal."
Barcelona's desire to sign a forward appears to show that Udinese star Alexis Sanchez is the club's top target this summer. Barca had appeared closer to a deal for the Chile international but Guardiola warned fans that there are no guarantees the signing will be completed.
"Udinese have a right to defend their interests," he said. "We made an offer and from there we negotiate. You can't expect to arrive and sign who you want just like that.
"The technical secretary [Andoni Zubizarreta] gave us four or five options for forwards and Alexis was the one we liked. If we complete the deal, great. If we can't reach an agreement, we'll go for a cheaper player or see what we have in the B team."
Guardiola also said that the decision to renew Thiago Alcantara's contract is entirely unrelated to the club's bid to sign Fabregas.
"The renewal of Thiago's contract has nothing to do with any deal for Cesc," he said. "It was always clear to us we wanted to keep Thiago. At his age, Xavi and Iniesta weren't playing at his level.
"Thiago has great talent and a lot of personality. He is really brave and daring. He faces a lot of competition in his position but we'll try to give him some minutes on the field."