Saudi Arabia rejected on Monday the idea of any foreign interference in Iraq and blamed Baghdad's "sectarian and exclusionary" policies for a lightning offensive by Sunni insurgents.
Rebels from the Islamic State of Iraq and the Levant (ISIL) have seized several Iraqi cities, threatening to split the country down sectarian lines, a deeply worrying prospect for the region and beyond.
The crisis "would not have happened if it wasn't for the sectarian and exclusionary policies that were practised in Iraq in past years and which threatened its security, stability and sovereignty", official news agency SPA cited Information Minister Abdulaziz Khoja as saying.
Sunni Muslim Saudi Arabia views Shia Iran as a potentially dangerous rival and like most Gulf Arab states is wary of its support for the Shia-led Iraqi government that came to power after Sunni president Saddam Hussein was forced from power by the 2003 US invasion.
In the government statement, Riyadh made no mention of possible talks on Iraq between Washington and Iran, something a senior US official said might happen on the sidelines of nuclear talks in Vienna this week.
But Riyadh said it was necessary to "preserve Iraq's sovereignty" and rejected any outside interference in Baghdad's internal affairs. It also urged the "quick formation of a national consensus government".
Earlier on Monday, Qatar's foreign minister blamed the "narrow" Shia sectarianism of Prime Minister Nuri al-Maliki's government in Baghdad for the crisis.
The remarks by Saudi Arabia and Qatar are likely to worsen relations with Baghdad, which has long accused both of them of backing the insurgents, something they deny.
The militants' gains followed "negative factors building up over a period of years", Qatar-based broadcaster Al Jazeera quoted Foreign Minister Khaled al-Attiyah as telling a conference in Bolivia on Sunday.
"(Baghdad has been) pursuing policies based on narrow factional interests, adopting marginalisation and exclusion, ignoring peaceful sit-ins, dispersing them by force, using violence against them and describing opponents as terrorists," said Attiyah.
Sunni Muslims, who dominated Shia-majority Iraq until the ousting of Saddam Hussein, have long complained of marginalisation and persecution under Maliki's Shia-dominated government.
Iraq's Sunni Vice-President Tareq al-Hashemi fled Baghdad in 2011 after the authorities issued a warrant for his arrest on terrorism charges.