The US State Department urged Egypt on Tuesday to be transparent over its security operation in the Sinai Peninsula, amid Israeli fears over the continued military build up in the territory.

State Department spokesperson Victoria Nuland said that the US fully supports Egypt’s military action to battle terrorism and increase security in the Sinai area, but added that coordination with Israel must continue according to the peace treaty between the two countries.

Victoria Nuland (photo credit: USGov/Wikimedia Commons)

Victoria Nuland (photo credit: USGov/Wikimedia Commons)

“We have encouraged that lines of communication stay open, in keeping with peace treaty obligations, and that they make full use of the mechanisms that are available for transparency, for confidence building, and we will continue to do so,” she said.

Jerusalem has expressed concern that Cairo failed to inform Israel that it had transferred tanks and military aircraft to the Sinai Peninsula as part of its campaign against Islamist terrorist organizations operating there.

On Tuesday, Israeli daily Maariv reported that Israel sent a missive to Egypt, via the White House, demanding that Egypt withdraw the extra forces, which violate the peace treaty between the two countries.

Later in the day, Foreign Minister Avigdor Liberman said that Israel must insist on the upholding of the provisions of the Israeli-Egyptian peace treaty, and not ignore Cairo’s mobilization of troops and equipment into the Sinai Peninsula without Jerusalem’s consultation.

“We need to be stubborn and insist on every single detail, otherwise it will be a slippery slope concerning the enforcement of the peace treaty,” Liberman said in a closed-door meeting with senior Israeli diplomats.

Nuland avoided confirming whether or not the US had acted as a go-between in the increasingly tense situation.

“Well, without getting into our private diplomacy with one country or the other, I would make the general point that as the Egyptians work hard now to defeat terror and turn back other security threats in the Sinai, we’ve been supportive of those efforts,” Nuland said. “We have encouraged them in those efforts, not only to enhance security in Egypt but also to enhance security for neighbors, security in the region.”

“Our understanding of the Egyptian security posture is that they are enhancing their posture to deal with security threats in Sinai. That’s obviously of security interest with regard to Egypt, but also with regard to neighbors. But as has been longstanding practice, there needs to be transparency, there needs to be confidence with neighbors.”

The 1979 Camp David Accords dictated that “no more than one division (mechanized or infantry) of Egyptian armed forces will be stationed” more than 30 miles east of the Suez Canal. Egypt has reportedly moved several M-60 tanks to the area surrounding the northern Sinai town of el-Arish, and plans on deploying aircraft and rocket launchers in a bid to root out terrorists from the peninsula.

Egypt has been mobilizing extra forces in the Sinai in a crackdown on terrorist targets there, after terrorists killed 16 Egyptian border guards in an August 5 attack at the Egypt-Gaza-Israel border. The terrorists then smashed across the border into Israel in a commandeered Egyptian army APC, before being blown up by the Israeli forces.

An Egyptian presidential spokesperson on Tuesday responded to Israeli criticism of the buildup saying that the Sinai counter-terrorism operation is essential to national security, and that Egypt received no request to remove its forces.

A senior official in Cairo also remarked to Reuters that Egypt is acting according to agreements made with Israel in the wake of the August 2011 cross-border terrorist attack in which six Israeli civilians and two soldiers were killed.

“Egypt is not obliged to send Israel a daily report on the operation in the Sinai,” the official added.

On Wednesday, former Israeli military intelligence chief Amos Yadlin said the Egyptian efforts were needed to battle terror that threatened Israel as much as Egypt.

“We need to look at this realistically,” he told Army Radio. “The Egyptians going in helps Israel in a large way.”

Jerusalem’s message to Cairo Monday was sent via the White House in an effort to give the warning added weight and to bridge the shaky relationship between Israeli and Egyptian security forces, Maariv reported.

Israel relinquished the Sinai, captured in the 1967 war, as part of its 1979 peace accord with Egypt. The treaty limited Egyptian military deployment in the area, to assuage Israeli security concerns. A mechanism built into the 1979 military annex provides for amendments to the framework of Egypt’s military deployment, coordinated by the Multinational Force and Observers (MFO) who are deployed there.