Hamas's comments come after days of increased military pressure by the IDF and diplomatic pressure from Qatar and Fatah.
Witkoff describes Hamas as being unreasonable in refusing a bridge to a peace deal at the end of the first phase of talks.
"I think Bibi believes that he's doing the right thing. I think he goes up against public opinion 'cause the public opinion [in Israel] wants those hostages home."
Witkoff also praised Netanyahu for his efficiency in decapitating Hezbollah and Hamas but noted his decisions to continue fighting heavily opposed Israeli public opinion.
Hamas claims to signal a willingness to release Israeli hostages if a ceasefire is resumed, according to an Al-Araby Al-Jadeed report.
Europeans have also warned Iran: If there is no agreement by June-July, "a significant wave of sanctions will be imposed," a source told The Jerusalem Post.
The terror organization stated that increasing military pressure would leave the remaining hostages "to an unknown fate."
Hamas has claimed that Israel broke the ceasefire, but it is Hamas that sought to stall since March 1, when the first phase ended.
As negotiators hit an impasse over hostage releases, US and Israeli officials warn Hamas that its "window of opportunity is closing" with possible military escalation if no deal is reached.
Talks continued throughout the weekend as a Hamas delegation led by Khalil al-Khayya visited Cairo for updates on the negotiations in Qatar.