Mr Gantz, a 59-year-old former general, earlier also claimed victory citing preliminary exit polls published soon after voting ended on Tuesday that showed his party had won more seats than Likud.
Pressed by Democratic Senator Tim Kaine - who described himself as "kind of shocked" that Pompeo would not reaffirm U.S. support for a two-state solution - the top USA diplomat said the United States wanted "good things" for the Palestinians but that a solution had to be acceptable to both sides.
"I'd like to congratulate Bibi Netanyahu", said President Trump after almost complete results put the incumbent premier in position to form a coalition.
The result of Abbas' policy toward the Trump administration will only be further harm to Palestinian interests.
The peace plan is being developed by Mr Trump's son in law, Jared Kushner. Few if any details have emerged, but Trump says there will be "some pretty good action" on the plan soon.
But even then Netanyahu appeared best placed to form a coalition, with both parties falling far short of an outright majority. He's set to meet with party leaders for their nominations, and he's announced that those meetings will be broadcast live to "ensure transparency for Israel's citizens".
Although the president acts largely in a ceremonial capacity, he is charged with choosing a candidate for prime minister after hearing recommendations from the heads of all factions, according to the Associated Press.
"With a new Israeli Government may yet come new opportunities for talks, but critically these must be between equals".
"We've had elections before where he didn't know the results but here it is even messier, " he said.
Netanyahu sought to portray himself as Israel's essential statesman during the campaign and highlighted his bond with Trump. But Likud has enough allies in the Knesset, Israel's national legislature, that Netanyahu can start forming a coalition government, reported USA Today. Netanyahu hasn't always followed through on election eve promises before, but should he follow through on this one, it would mark a dramatic development and potentially wipe out the already diminishing hope for Palestinian statehood. But the victor might not be announced immediately as no party has ever won an outright majority in parliament. We have a historic achievement under our belts. "Four months ago he created a party that is now at least tied for being one of the largest parties today, and bigger than any party has been in recent memory, maybe 10 years or so", Barak said. In December, when these elections were called, 73% of voters said they wanted a right or centre-right government.
He faced a tough challenge from Gantz, who offered the security credentials prized by Israelis and a clean-hands image, but lacked the political experience the prime minister accrued in a combined 13 years in office.
The Palestinian issue and prospects for peace negotiations were notably absent from political debate this election.