Installed to monitor the demilitarization of the Sinai under the 1979 Egyptian-Israeli peace accord, the Multinational Force and Observers (MFO) and some of its 12 contributor countries have been considering changes to its deployment and mandate.
They worry about the safety of the almost 1,900 peacekeepers after six were wounded in September by a roadside bomb.
At a time of heightened security concerns in the region, they have argued that dismantling more remote and vulnerable posts would not significantly set back the mission - especially at a time when Egypt and Israel say their counter-insurgency ties are closer than ever.
But both countries favor the MFO status quo and, at a review meeting held in Rome last week and attended by a US delegation, they stood firm, according to one Egyptian official.
"The MFO said they want to reduce the force now, but we and Israel refused," the official told Reuters on condition of anonymity, adding that the MFO had proposed withdrawing some 400 troops over six to nine months and replacing them with remote surveillance equipment.
"We said this is not the proper time, during a war on terrorism. It would give jihadists the wrong message," the official said. "That was the main outcome: No talks about any reduction now."
Cairo sees the MFO as part of a relationship with Israel that, while unpopular with many Egyptians, brings them $1.3 billion in annual US defense aid, sweetening the foreign-enforced demilitarization of their sovereign Sinai territory.
For the Israelis, the MFO offers strategic reassurance, recalling that two years ago Egyptian President Abdel Fattah al-Sisi toppled an elected Islamist regime hostile to the Jewish-majority state next door.
MFO and US officials had no immediate comment. An Israeli official declined to discuss the Rome meeting but appeared to confirm common cause over maintaining the MFO.
"Israel and Egypt are interested in the force remaining with its current disposition," the official told Reuters.
Egyptian security efforts in the Sinai have suffered major setbacks, including the Oct 31 downing of a Russian airliner and Tuesday's deadly bombing of a hotel where judges were staying.
Islamic State insurgents claimed responsibility for both incidents.