Iraqi Prime Minister Haider al-Abadi said the Kurdistan Regional Government's (KRG) planned referendum on independence was "unconstitutional" on Tuesday, hours after parliament voted against the regional plebiscite.

"I call upon the Kurdish leadership to come to Baghdad and conclude the dialogue," Abadi said in a press conference.

Abadi's remarks came after the Iraqi Parliament vote to reject the independence referendum planned for Sept. 25, authorizing the prime minister to take all measures to preserve Iraq's unity.

The Iraqi prime minister added that if the KRG insists on holding a referendum, the Kurdistan region will "lose" all it has achieved since the U.S.-led invasion of Iraq in 2003.

Northern Iraq-based news outlet Rudaw reported that Abadi said, "The Kurdish citizens in Iraq made achievements during the period of coexistence after 2003 that they could not achieve in past centuries. And this is their right, because they are first-class citizens like all other Iraqis."

He was making reference to the Iraqi Constitution that came in effect in 2005, which recognized the Kurdistan region established in 1992 with its own parliament, armed forces and government.

On Tuesday, KRG leader Massoud Barzani said he would press ahead with the Sept. 25 referendum despite a vote by Iraq's parliament rejecting it.

Since the KRG announced its plan to hold the referendum, it has gained little support from the international community and instead has faced some harsh criticism.

The non-binding referendum has faced strong opposition from neighboring Iran and Turkey, as both countries warned the KRG several times to withdraw its decision to hold a referendum.

The EU also declared its support for the territorial integrity of Iraq while the U.S. and Kurdish opposition Goran Movement demanded the postponement of the referendum.

Only Israel openly supports the referendum and independence of the KRG. Israeli Prime Minister Benyamin Netanyahu endorsed the independence of the KRG yesterday, saying, "[Israel] supports the legitimate efforts of the Kurdish people to achieve their own state."

Netanyahu, in remarks sent to foreign correspondents via his office, added that Israel does, however, consider the PKK a terrorist group, taking the same position as Turkey, the U.S. and the EU.

Netanyahu's statements came in response to Yair Golan, a major general and the former deputy chief of the General Staff in the Israel Defense Forces (IDF), who said that he personally does not regard the PKK as a terrorist group, speaking at a conference in Washington last week.