Fourteen more Israeli hostages and three foreign nationals were released to the Red Cross on Sunday by Hamas, according to an Israel Defense Forces spokesperson.

At least one of the foreign nationals is Russian, according to a statement by the Al-Qassam Brigades, Hamas' military wing.

"In response to the efforts of Russian President Vladimir Putin and in appreciation of the Russian position in support of the Palestinian cause, the Islamic Resistance Movement Hamas has released a detainee of a Russian nationality," the statement said.

No Americans were among the hostages released.

"As part of the humanitarian truce and within the third phase of the exchange, we handed over to the Red Cross 13 Israeli detainees, 3 Thai detainees, and one Russian detainee," the Al-Qassam Brigades said in another statement.

-ABC News' Ayat Al-Tawy and Becky Perlow

One American hostage could be released from Gaza on Sunday as part of a prisoner exchange between Israel and Hamas, White House national security adviser Jake Sullivan told ABC "This Week."

"This first set of hostages, 50 hostages over four days, is women and children -- and three Americans [are] in that category, two women and one child," Sullivan told "This Week" co-anchor Jonathan Karl. "We have reason to believe one of those Americans will be released today."

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‘Hamas gained some benefits’ from temporary cease-fire deal: Jake Sullivan

ABC News’ Jonathan Karl interviews White House National Security Adviser Jake Sullivan on “This Week.”

Still, Sullivan cautioned, "Until we actually see her safe and sound ... we cannot have 100% certainty that it will happen. So we're going to watch this hour by hour and hopefully have a moment of joy where one of the Americans is safely out and ultimately reunited with her family. That's what we are waiting for as we speak."

-ABC News' Tal Alexrod

Egypt's State Information Service said another 13 hostages will be freed by the Hamas terror group Sunday after 51 days in captivity in Gaza.

Israel is expected to free 39 Palestinian prisoners held in Israeli jails on Sunday as part of the negotiated agreement, Egyptian officials said.

-ABC News' Ayat Al-Tawy

The International Committee of the Red Cross said it facilitated the release on Saturday of 33 Palestinian detainees from Israel to the West Bank.

A bus carrying the detainees arrived in Al Bireh in the West Bank early Sunday, The Associated Press reported.