"The US remains focused on a two-state solution and will continue to work with the parties to narrow differences on core issues," he added.
His remarks came after the pan-Arab satellite channel Al-Jazeera said it had obtained a trove of "secret documents" from the last 10 years of failed peace negotiations revealing major concessions by the US-backed Palestinian leadership, including on the sensitive future status of Jerusalem.
Chief Palestinian negotiator Saeb Erakat, quoted in several of the documents, dismissed most of the report as a "pack of lies" and insisted the Palestinian Authority had "nothing to hide."
Israeli-Palestinian peace talks last broke down in September following the expiration of a limited moratorium on Israeli settlements.