But Kerry said he is not optimistic about the U.S.-Russian relationship, though, "I have hope."
"I would like to see if we can find some way to cooperate," Kerry told the Senate Foreign Relations Committee, which he still heads. "We need their help and cooperation with respect to [ending the civil war in] Syria.
"I would also say that with respect to Russia, Russia has helped on a number of different things that are critical to us, and people should not overlook them," Kerry said. "They did cooperate on the START Treaty itself. They did cooperate on the P-5-Plus-1 [the five permanent members of the U.N. Security Council plus Germany] and are cooperating today in that initiative [to prevent Iranian nuclear weapons]. They have cooperated on the sanctions [against Iran]. ...
"I think it's fair to say that everybody here knows that [Russian leaders] warned us and said, 'If you do X, Y or Z on such-and-such a thing we may respond,' and we've gotten into that little back-and- forth. So we're gonna have to work our way through it. I'm confident we can."
Kerry warned he was not totally sanguine about the relationship.
"I don't want inquisitiveness or curiosity about what possibilities might exist with the Russians to be translated into optimism. I don't have optimism. I have hope."
As for the Syrian civil war, "The Russians have indicated -- and I've had personal conversations prior to being nominated to secretary with Foreign Minister [Sergey] Lavrov which indicated a Russian willingness to in fact see President [Bashar] Assad leave, but they have a different sense of the timing and manner of that."