WASHINGTON/CAIRO - The United States supports Egypt’s recent military deployments to the Sinai Peninsula but said late Tuesday that Cairo must coordinate such action with Israel and observe the 1979 peace treaty, while Egypt’s President Mohmmed Mursi, the country’s first civilian and Islamist head of state, will visit the US on September 23, state television reported on Wednesday.

“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,” said US State Department spokeswoman Victoria Nuland in Washington.

“We have encouraged them in those efforts not only to enhance security in Egypt but also to enhance security for neighbours, security in the region,” she said, referring to Israel.

Israeli Prime Minister Benjamin Netanyahu recently urged Cairo to withdraw tanks deployed near the border in Sinai, which aimed to suppress Islamist groups, Israeli newspaper Maariv reported.

And in a message sent to Cairo via the White House, Israel demanded that Egypt stop deploying more troops to the region without Israeli cooperation - in observation of the 1979 peace treaty between the nations.

That agreement stipulated the Sinai’s demilitarization, but a senior Israeli official told Maariv that the recent deployments were a troubling violation of the peace accord.

Egypt faces a serious crisis in the Sinai, where 16 border guards were killed on August 5 by a group of Islamists, who subsequently infiltrated Israeli territory and were killed by tank and helicopter fire.

In the wake of the attack on the army outpost, recently elected Egyptian President Mohamed Mursi dismissed his defence minister, replaced his spy chief and sacked top security and political officials in the Sinai.

On August 14, Egyptian security forces exchanged fire with militants in the peninsula and on August 18, militants wounded three policemen there in an ambush of their vehicle with a rocket-propelled grenade.

The tribes of the Sinai, an area mainly populated by Bedouins, have long had strained relations with the central government, which they accuse of neglecting the development of the peninsula.

The military campaign has seen the largest build-up of troops in the Sinai since Israel returned the territory under the 1979 peace treaty.