Secretary of State John F. Kerry is leading an increasingly public U.S. effort to persuade Persian Gulf nations to help pull Iraq back from the brink of civil war, leaning on them to use their influence with Iraq’s Sunni tribes and suggesting that open hostility to Shiite Prime Minister Nouri al-Maliki will only backfire.

The Obama administration is trying to rally wealthy Arab states to help extinguish support for the Islamic State of Iraq and Syria (ISIS), a Sunni militant group, among Iraq’s disaffected Sunnis. The al-Qaeda offshoot, now disowned by the terror syndicate, has exploited Sunni anger against the Shiite-led central government in Baghdad to blitz through western and northern Iraq, amassing territory, cash and weapons.

The militants’ stunning success threatens neighboring countries, including Jordan, and deeply unnerves the authoritarian Sunni dynasties ruling Saudi Arabia, the United Arab Emirates and other Arab nations.

“The move of [ISIS] concerns every single country here,” Kerry said Thursday as he convened a meeting among top Saudi, Emirati and Jordanian diplomats that also covered developments in Syria and Iran.

“I think with the cooperation between the countries, we can affect hopefully the situation in a better way,” longtime Saudi Foreign Minister Saud al-Faisal said.

Kerry will fly to Saudi Arabia on Friday to meet with King Abdullah, considered the single most important voice among the gulf nations. The usually tight U.S. bond with Riyadh has been deeply tested in the past year, particularly over President Obama’s decision last summer not to launch airstrikes against Syria. Saudi Arabia also is nervous about the possibility of U.S. rapprochement with Iran, its principal Shiite enemy.

The United States and Saudi Arabia were taken aback by ISIS’s swift success in Iraq this month and by the support it has garnered from Sunni tribes and other Islamist militias. Saudi Arabia, although bitterly opposed to Maliki and his government’s treatment of Iraq’sIraq’s minority Sunnis, is against any U.S. or other foreign intervention.

Iraq’s Sunni neighbors, notably Saudi Arabia, have long inveighed against Maliki. Last week, the Saudis publicly called for him to go, while pushing the United States behind the scenes to yank all support for Maliki as Iraq looks to form a new government after recent parliamentary elections.

Kerry met with Maliki in Baghdad on Monday, but U.S. officials have declined to publicly endorse him and have openly met with his political rivals. The United States backed Maliki through two elections, despite reservations about his Shiite partisanship. He has shrugged off U.S. calls for political inclusion but was considered more likely than other potential Shiite leaders to make some attempt at outreach to Sunnis and to be less beholden to Iran.

Maliki is maneuvering to retain power when parliament convenes Tuesday to begin selecting new leadership. There is no obvious alternative among leaders of the various Shiite splinter parties that form Maliki’s coalition, Iraq analysts said, and he could again emerge as the consensus candidate.

“The United States is not disinterested in what happens in a future leadership, but the United States is not going to engage in the process of suggesting to Iraqis who that ought to be,” Kerry said in Brussels after NATO meetings. He also briefed other foreign ministers on his trip to Iraq.

“The views of the current [Iraqi] government were made clear” in the meeting with gulf states Thursday, a senior State Department official said afterward. “Our response to that is, again, ‘The most constructive use of your energy is to encourage the political process to continue to move forward, not to focus on the perceived transgressions of past years.’ ”

The official spoke on the condition of anonymity to describe the closed-door session at the home of the U.S. ambassador in Paris.

Privately, other U.S. officials have expressed some exasperation at the Saudi position, calling it counterproductive because it might stoke Shiite nationalism that Maliki could exploit.

Douglas Ollivant, a former director for Iraq on the National Security Council, agreed.

“I can’t think of a better way to make sure he remains than to have the Saudis insisting that he go,” said Ollivant, now a managing partner at Mantid International. “File that under ‘not helpful.’ ”