"Israel stands at the forefront with the Jewish community of Pittsburgh, with all Jewish communities in the U.S. and with the American people," Netanyahu said at the start of the weekly government cabinet meeting. "We stand together, at the forefront, against anti-Semitism and displays of such barbarity."
Before the meeting began, ministers held a moment of silence to honor those killed in the attack.
"I call upon the whole world to unite in the fight against anti-Semitism everywhere," Netanyahu said. "Today, regretfully, we refer to the United States, where the largest anti-Semitic crime in its history took place, but we also mean, of course, Western Europe, where there is a tough struggle against the manifestations of a new anti-Semitism," as well as radical Islam, he said, adding that "it begins with Jews but it never ends with Jews."
"On all these fronts we must stand up and fight back against this brutal fanaticism," Netanyahu said.
Saturday morning, a heavily armed white man in his 40's entered the Tree of Life Congregation Synagogue in Pittsburgh and killed 11 people during a Shabbat service. Before the attack, he yelled out, "All Jews must die."
'Important talks in Oman'
The prime minister also spoke of his visit to Oman, saying it "comes against the background of diplomatic efforts that I have been promoting in recent years vis-a-vis the Arab countries."
Netanyahu said he and Omani leader Sultan Qaboos bin Said "discussed in detail the challenges facing the Middle East. These were important talks - both for the State of Israel" and its security, adding there would be more talks in future.
Addressing the mounting tensions in Gaza, Netanyahu referred to a report by the Israeli News Company on Saturday that Hamas issued an ultimatum to Israel.
According to the report, Hamas' chief in Gaza, Yahya Sinwar, demanded that Israel transfer Qatari funds, which are meant to pay Hamas wages, by Thursday - or the organization will turn up the heat on the border protests. Specifically, Hamas demanded $15 billion a month to maintain the calm in the region.
The demand is meant to circumvent the current supervision apparatus, through which Palestinian Authority Mahmoud Abbas paid the salaries with relative transparency. Sinwar's stipulation would allow the terror organization to funnel the money directly to its military branch.
"At no stage will Israel accept any ultimatum from Hamas. Israel will continue to act in accordance with Israeli interests and for Israel's security alone," Netanyahu said.