UNITED NATIONS — As sniping and rocket launching across the border between the Hamas-controlled Gaza Strip and the Israeli Negev were described as “war” by Prime Minister Olmert, President Abbas of Palestinian Authority threatened to quit peace talks and even to resign his post, according to a report on the State Department-sponsored Radio Sawa.

The sharp increase in the number of rockets launched from Gaza into Sderot and other southwestern Israeli towns and the deadly Israeli air raids against Hamas and other Gaza-based terrorist operatives, threatened to quickly erase whatever hopes of reinvigorated diplomacy were raised last week during President Bush’s Middle East visit.

More than 100 rockets fell in southern Israel in the last two days, a sniper killed an Ecuadorian volunteer working in the fields of an Israeli kibbutz near the Gaza Strip, and — showing an ever-increasing military capability and versatility — Gaza’s various armed groups terrorized Israel’s population across a widening number of nearby towns as far as Ashkelon and Ashdod, where an early warning system was installed yesterday for the first time.

According to military sources, Gaza’s rockets may soon be able to reach the Tel Aviv metropolitan area.

Defense Minister Ehud Barak vowed to find a military solution. “It will not be simple. It may not happen over the weekend, but we will bring an end to the Kassam shooting on Sderot,” he said during a visit to the area, according to press reports. He said that in the next few days, Israel intends to temporarily block all Gaza entry points, as it continues to target militants.

Twenty-three Palestinian Arabs, most of them armed men, were killed in the last two days in Israeli air raids. Hamas’s seizure of Gaza from the Palestinian Authority had been described by a rival group, Mr. Abbas’s Fatah Party, as a “putsch,” but yesterday, Mr. Abbas reportedly called the Hamas top leader, Mahmoud Zahar, to express condolences after Israel was able to kill Mr. Zahar’s son, who was also a member of the terrorist group.

“In off-the-record conversations, Abu Mazen is cheering us, as we are doing what he is, in fact, supposed to do in fighting Hamas,” an Israeli official said, referring to Mr. Abbas by his nickname and speaking on condition of anonymity. Publicly and often in press leaks, however, Mr. Abbas makes statements of solidarity with Gaza and expresses outrage at Israel’s actions.

An unnamed source in Mr. Abbas’s office wrote to the Gaza offices of Radio Sawa to say the Palestinian Authority chief is “considering the possibility of ending negotiations with Israel because of the continuing raids on the Gaza Strip,” according to the American government-owned broadcast network’s Web site.

As part of a series of “communications” with American and European diplomats, as well as in consultations with Prime Minister Qurei, who heads the Palestinian Authority’s diplomatic negotiations team, Ms. Rice pressed Mr. Abbas not to quit the talks, according to the report, which also said Mr. Abbas “threatened to resign” from his post and to dissolve the Palestinian Arab negotiation teams.

A State Department spokesman, Robert McInturff, told the Sun he was “unable to confirm” the veracity of yesterday’s report. According to a follow-up report on Israel’s NRG web site, Ms. Rice said she would talk to Mr. Olmert, to lean on him to end the Gaza attacks. “We haven’t heard of this,” a spokesman for Mr. Olmert, David Baker, said. “Israel will do what is necessary to end the daily lethal attacks” from Gaza, he said. “A war is going on in the south, every day, every night,” Mr. Olmert told an industrialists conference in Tel Aviv. Speaking of the killing of Hamas and Islamic Jihad operatives, he added, “They have been hit, and this is not the last hit they are going to suffer.” Separately, Israel tested a new ballistic missile yesterday, which according to Israel Radio was able to “carry an unconventional payload.” The test, described as successful, came after Mr. Olmert on Monday said Israel would not allow Iran to obtain nuclear weapons, using “all options” at its disposal.

The “Zionist regime” would “not dare to attack Iran,” President Ahmadinejad retorted in an Al-Jazeera interview. “The Iranian response would make them regret it, and they know this,” he said.