TEL AVIV // Avigdor Lieberman, Israel's ultranationalist foreign minister, said yesterday there was "no chance" his country would agree to amend its historic peace treaty with Egypt, in a statement that could escalate tensions.
Mr Lieberman's comment comes days after an adviser to Mohammed Morsi, the Egyptian president, said it was "a matter of time" before the pact is changed to bolster Egypt's control over the Sinai peninsula, which borders Israel.
Egypt and Jordan are the only Arab countries to have signed peace agreements with Israel, and the 1979 treaty between the Israelis and Cairo is considered a cornerstone of regional peace.
Officials in the government of Mr Morsi have said they want to revise the pact to allow Egypt to bring more troops into Sinai, which under the agreement is largely demilitarised, to fight increasing violence there.
Israel is concerned, however, that making such changes permanent would endanger its security and leave its 250-kilometre border with Egypt vulnerable should ties with Cairo deteriorate.
Analysts say Israel is also worried that allowing changes to the pact's security annex would open the possibility for Egypt to request more controversial revisions.
Mr Lieberman said: "There is no chance that Israel would agree to any kind of change" to the agreement. He added that the Egyptians "should not rely on this demand".
He suggested that Egypt may not be sufficiently prepared to fight the lawlessness in Sinai. He said: "The problem in Sinai is not the size of the forces, it is their readiness to fight, to put pressure and to carry out the job as is needed."
Violence along the Israeli-Egyptian frontier as well as within Sinai has been a key source of anxiety for both Israel and Egypt since the uprising that overthrew Hosni Mubarak last year.
On Friday, an Israeli soldier on the border was killed and another wounded by militants wearing explosive belts who infiltrated into Israel. Yesterday, an Islamist group, Ansar Bayt Al Maqdes, claimed responsibility for the attack.
A statement from the group said the killings were in response to the anti-Islam film, Innocence of Muslim that spurred protests across the Muslim world.
There have been at least four such cross-border strikes in the past year targeting Israeli soldiers. The pipeline delivering gas from Egypt to Israel has also been repeatedly attacked and rockets have been fired from Sinai into Israel. Egypt has also been targeted, with 16 of its soldiers killed by Islamist gunmen in August.
Until recently, Sinai, which Israel returned to Egypt in 1979, was a relatively peaceful region. However, in the past few years and especially since Mr Mubarak was toppled, it has become volatile as groups inspired by, or with loose ties to Al Qaeda, became more active there.
Israel has allowed Egypt to bolster its military presence in Sinai in recent months as a temporary measure.
In August, Egyptian troops moved into the most sensitive zone in Sinai near the Israeli border in a coordinated exercise with Israel.
But Israeli experts are divided on whether Israel should make permanent changes to the pact.
Elie Podeh, a professor of Middle East studies at Jerusalem's Hebrew University, said Israel should continue negotiating temporary revisions.
"In light of the changes in the Middle East, Israel needs to be more cautious," he said. "Today the ties with Egypt are very delicate and the potential for deterioration is very much there."
Avraham Sela, an Israeli expert on Israeli-Egyptian relations, said Israel and Egypt shared a mutual interest to stem violence in Sinai and that Israel should be open to a stronger Egyptian presence.
He added, referring to Mr Lieberman's statements: "This Israeli government is a master at creating an atmosphere of hysteria. The Egyptian requests are quite modest at the moment and Israel should sit down with Cairo and find a way to respond to the real threats from Sinai."