BAGHDAD, IRAQ — Saudi Arabia declared yesterday that it held Iraq’s Shiite-led government responsible for its sectarian strife and warned that America’s new war strategy would fail without a radical change of heart by the Baghdad leadership.

Secretary of State Rice met Saudi leaders in Riyadh as part of a Middle East tour to shore up support from Washington’s Middle Eastern allies for efforts to counter Iran’s spreading influence in Iraq.

After meeting Ms. Rice, the Saudi foreign minister, Prince Saud al-Faisal, said: “We agree fully with the goals set by the new strategy, which in our view are the goals that, if implemented, would solve the problems that face Iraq.

“Implementation also requires a response by the Iraqis to these goals. Other countries can help but the main responsibility in taking decisions rests on the Iraqis.”

Saudi Arabia watched in horror as Shiite leaders, many of them beholden to Tehran after years of exile there, assumed power in Baghdad following the overthrow of Saddam Hussein.

As conflict spiraled in Iraq, the Sunni rulers of Riyadh moved to prevent it spilling over by building a security fence along their border.

Saudi leaders have hinted that the oil-rich state is ready to help Iraqi Sunnis defend themselves against Iranian-backed Shiite militias.

A leading member of the clerical elite has said Tehran’s influence in Iraq is the most serious threat facing their kingdom. “Iran has become more dangerous than Israel itself,” said Sheik Musa bin Abdulaziz, the editor of Al Salafi magazine. “The Iranian revolution has come to renew the Persian presence in the region. This is the real clash of civilizations.”

Nawaf Obeid, an adviser to the Saudi government, was fired for warning of a future intervention “to stop Iranian-backed Shia militias from butchering Iraq’s Sunnis.”

The Sunni monarchy fears that the rise of Shiite Arabs in Iraq may lead to unrest among its own Shiite population, which forms a majority in the main oil-producing region.

President Bush is sending 17,500 troops to Baghdad to quell the violence. Prime Minister al-Maliki, previously vetoed American attempts to tackle Shiite militias responsible for the murder of tens of thousands of Sunnis but has promised to support the latest effort.

The power of Tehran’s allies in Iraqi politics far outweighs any other faction. Leaders of both Iraq’s leading Shiite political parties were exiled in Iran and still draw funding from Tehran. And the arrest of five Iranian Revolutionary Guards last week forced even the most pro-American members of the Baghdad cabinet to side with Tehran.

Iraq’s foreign minister, Hoshyar Zebari, appealed for America to back away from confronting Iranian interests in Iraq. “You have to remember, our destiny, as Iraqis, we have to live in this part of the world. And we have to live with Iran, … with Syria, and Turkey.”

Iraq’s once dominant Sunni elite is almost totally disenfranchised, upsetting the balance of power in a region were ethnic and religious groups constantly vie for supremacy.

Vice President Tareq al-Hashemi, a Sunni, has disclosed that government ministers discussed openly providing strategic support for sectarian militias to extract revenge for terrorist atrocities.

President Ahmadinejad of Iran is facing growing opposition at home, with newspapers and members of Parliament accusing him of being too aggressive toward the West. A petition is said to be circulating to summon him to answer to parliament.

He was attacked for spending the weekend meeting leftist leaders in Latin America at a crucial time for his country.

“While Condoleezza Rice, Iran’s nuclear file in hand, is in the region talking to Iran’s Arab neighbors, the Iranian president is lauding the victory of socialism in Latin America,” said the reformist daily Etemad Melli.