Demonstrators shout slogans during a rally in support of the Palestinians, after Israel's eight-day military operation in the Gaza Strip, in Rabat, Morocco, Nov. 25, 2012. (Xinhua/File Photo)

UNITED NATIONS, Sept. 15 (Xinhua) -- UN Secretary-General Ban Ki-moon on Thursday warned that a two-state solution to the Israeli-Palestinian conflict is heading toward a "one-state reality" if the international community failed to encourage the both sides to take the difficult steps to bring peace and security between them.

The secretary-general, while speaking at the UN Security Council on the situation in the Middle East, said, "Twenty-three years ago, almost to the day, the first Oslo Accord was signed between Israel and the Palestine Liberation Organisation."

"Unfortunately, we are further than ever from its goals," Ban said. "The two-state solution is at risk of being replaced by a one-state reality of perpetual violence and occupation.

The two-state solution, widely backed by the international community, means a secure Israel to live in peace with an independent State of Palestine.

"Despite warnings by the international community and the region, leaders on both sides have failed to take the difficult steps needed for peace," he said.

Just on Wednesday, militants in Gaza fired yet another rocket into Israel, which he condemned, the secretary-general said, adding that Israel fired four missiles at targets in Gaza in response.

"Once again I reiterate that such attacks and the response they elicit do not serve the cause of peace," he said.

In the past two weeks alone, plans were advanced for yet another 463 housing units in four settlements in Area C of the occupied West Bank, he noted. "Official Israeli data shows that the second quarter of 2016 had the highest number of construction starts in three years."

"The decades-long policy that has settled more than 500,000 Israelis in Palestinian territory is diametrically opposed to the creation of a Palestinian state," he said.

"Regrettably, the reporting period also saw the continuation of statements by both sides that only perpetuate an environment of mistrust," he said.

"I am disturbed by a recent statement by Israel's Prime Minister (Benjamin Netanyahu) portraying those who oppose settlement expansion as supporters of ethnic cleansing," he said. "This is unacceptable and outrageous."

"Let me be absolutely clear: settlements are illegal under international law," he said. "The occupation, stifling and oppressive, must end."

"The international community, including the Security Council and the Middle East Quartet, universally views the expansion of settlements as an obstacle to peace," Ban added.