Sagna was reportedly disappointed with the terms of the 12-month extension offered by Arsenal, with the full-back said to be seeking a longer deal and more than his current £60,000-a-week wages.
However, Wenger maintains those reports are misleading and the France international is on course to sign a new contract with the Gunners.
"I do not understand these speculations," Wenger said ahead of Saturday's Premier League clash against West Brom at Emirates Stadium.
"He has one-and-a-half-years of his contract to go, and we are in negotiations with him to extend the contract which are very positive, so I am quite amazed by these statements because it is completely opposite of the feelings we have with the player, and with the negotiations we have about his extension."
However Wenger admitted he is frustrated about the lack of progress in tying down Walcott on a new deal.
The 23-year-old England international is out of contract at the end of the season and there has been speculation that he may be sold in the January transfer window.
Wenger said: "With Theo, I have no news. I personally am not involved in that directly, indirectly of course yes, but at the moment we have not made any progress.
"Honestly, I am frustrated. Between the player and me it is all clear, he knows what he wants and he has to make up his mind."
Wenger added: "We have been in negotiations with Theo for a long, long time, and we have not been late in our renegotiations with him.
"We always try to extend the contracts very early."
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