Two US presidents on Saturday were set to pay tribute to slain prime minister Yitzhak Rabin, as Israel marked the 20th anniversary of his assassination in the Tel Aviv square where the memorial rally was being held.

President Barack Obama was to address the thousands of people gathered at the event in a speech to be played on large screens.

Former president Bill Clinton, who has repeatedly paid tribute to Rabin over the years since his murder, arrived in Israel earlier this week and was to speak in person at the memorial.

Major Tel Aviv streets were closed off to traffic, including Ibn Gvirol, Ben Gurion, Frishman and Malchei Israel. By 8 pm, the square was packed with tens of thousands of people for the start of the event; later, police estimated the attendance figure at 100,000.

Clinton on Friday met with Prime Minister Benjamin Netanyahu and President Reuven Rivlin.

Rivlin, who was also to speak at the event, said Clinton’s attendance was “a clear testament” to his kinship with the Jewish nation.

During their meeting Friday, the two discussed recent developments in the region, including Israeli-Palestinian tensions, unrest and the almost daily attacks against Israelis over the past month.

Former US president Bill Clinton meets with President Reuven Rivlin in Jerusalem on October 30, 2015 (GPO)

Former US president Bill Clinton meets with President Reuven Rivlin in Jerusalem on October 30, 2015 (GPO)

The rally on Saturday night, at the square that now bears Rabin’s name, capped a week of commemorative events in Israel, which have included a state ceremony at Mount Herzl and a special Knesset session.

Rabin was slain on November 5, 1995, by Jewish extremist Yigal Amir at the same plaza that will host Saturday’s rally.

In his eulogy for Rabin at the state funeral in Jerusalem following the assassination, Clinton memorably ended with the words “Shalom, chaver,” or “Goodbye, friend.”

In a 2013 Channel 2 interview broadcast for the first time Monday night, Clinton said that had Rabin lived, the Israeli leader would have been able to reach a peace deal within three years, because “the Palestinians trusted him.” The interview, which was filmed on Clinton’s last trip to Israel in June 2013, was broadcast to coincide with the 20th anniversary of the assassination.

Clinton, highly emotional throughout the interview, said that he “really loved the man” and that he had expected they would both “live 20 more years, and I would come here [to Israel] and see him every chance I could.