Steve Witkoff's comments to Fox News appeared to be the first public confirmation of the planned use of outside inspectors in the Gaza Strip, including a presence by US officials.
Israel and Hamas struck a multi-phase deal last week to cease fire and release hostages held by the militants, after months of mediation by the US, Qatar and Egypt.
Trump demanded a deal before he took office on January 20.
The deal took effect on January 19.
Witkoff told Fox he was focused on ensuring the deal moves from its initial six-week phase to its second phase, which mediators say is expected to include the release of all remaining hostages and a complete withdrawal of Israeli soldiers.
"I'm actually going to be going over to Israel. I'm going to be part of an inspection team at the Netzarim corridor, and also at the Philadelphi corridor," Witkoff said.
Netzarim is an east-west strip Israel cleared during the war that prevents Palestinians' free movement between the north and south of the Gaza Strip.
Philadelphi is a narrow border strip between the Gaza Strip and Egypt.
US President Donald Trump called the Gaza Strip a "demolition site" following Israeli bombardment. (AP PHOTO)
"That's where you have outside overseers, sort of making sure that people are safe and people who are entering are not armed and no one has bad motivations," Witkoff added.
Witkoff did not say who else might be part of the inspection team.
Israel's military and defence ministry did not immediately respond to requests for comment.
A source familiar with the ceasefire deal said Witkoff was expected to be in Israel frequently.
"He intends to be here and monitor, especially toward the second phase of the agreement."
Under the terms of the ceasefire, Israel must withdraw its troops from centre of the Gaza Strip and permit the return of Palestinians to the north during an initial six-week phase, in which some hostages will be freed in exchange for the release of Palestinian prisoners.
Trump said on Monday that he was not confident in the ceasefire deal, and described the Gaza Strip as a "massive demolition site" following months of Israeli bombardment.
After the ceasefire was struck, Trump said he would build on the deal's momentum to expand the Abraham Accords, a series of agreements reached during his first term in which Israel normalised ties with Arab countries including the United Arab Emirates.
During the Fox interview, Witkoff was asked which countries in the region might join the accords.
"I think you could get everybody on board in that region. I really do. I think there's a new sense of leadership over there," Witkoff said.
Asked to name a specific country, Witkoff said: "I mean, Qatar."
"Qatar was enormously helpful in this. Qatar's (Prime Minister) Sheikh Mohammed, (his) communication skills with Hamas were indispensable here," Witkoff said.
