RIYADH—Saudi King Abdullah is turning out to be the most prominent foreign supporter of Egypt's military generals in their armed push against Egypt's Islamic movement, sending field hospitals and words of support over the weekend for what he called Egypt's fight against "terrorism and extremism."

The Egyptian military's crackdown, part of violence that Egyptian authorities said has killed roughly 1,000 people since Wednesday, also appears to have revealed a new split between Saudi Arabia and its close ally, the U.S.

Saudi Arabia's King Abdullah REUTERS

The Obama administration last week canceled a planned joint military exercise with Egypt to protest the Egyptian government's bloody breakup of sit-ins by the Muslim Brotherhood.

The U.S. has urged curbing the violence between Islamists and Egypt's government, while stopping short of threatening to cut off military aid to the country.

In a comparatively rare public foreign-policy statement read Friday on Saudi television, King Abdullah declared that what was happening in Egypt was an Arab affair. "Let it be known to those who interfered in Egypt's internal affairs that they themselves are fanning the fire of sedition and are promoting the terrorism which they call for fighting," he declared, without mentioning any country by name.

Who is the Muslim Brotherhood? Mirette Mabrouk, deputy director at the Atlantic Council's Rafik Harari Center for the Middle East, joins the News Hub to discuss. Photo: AP.

Timeline: Egypt in Transition

Associated Press

King Abdullah and Saudi Arabia have faulted the U.S. response to events in Egypt before.

In early 2011, Saudis expressed bitterness at the U.S. urging then-Egyptian President Hosni Mubarak, a longtime ally of Saudi Arabia and the U.S., to cede to popular demands to surrender power.

Saudi analysts at the time said that the Saudi perception that the U.S. had abandoned Mr. Mubarak contributed to the Saudi kingdom's decision to send troops around the same time to prop up the government of neighboring Bahrain amid public demonstrations there.

The kingdom's quick support for the Egyptian military this month and last underscore the extent to which security and the rolling back of political Islam have preoccupied the Saudi monarchy since the Arab revolutions.

Most of the king's public statements in recent months have focused on the perceived threat from religious movements like the Muslim Brotherhood, which officially is banned in Saudi Arabia.

On Saturday, the Saudi government said it was sending three field hospitals to Egypt in the interests of "standing by and supporting the brotherly Egyptian people" amid continuing street violence there.

Saudi Arabia and the fellow Gulf monarchies of Kuwait and the United Arab Emirates in early July pledged $12 billion in aid to Egypt. The support came within days of the Egyptian military taking into custody the elected Egyptian President Mohammed Morsi, an ally of the Muslim Brotherhood.

Though allies, Saudi Arabia and Egypt have long vied to be the top regional power. The Arab revolutions that began in 2010 unseated many of the autocrats with whom a succession of Saudi rulers had felt comfortable, such as Egypt's Mubarak, and for a time strengthened the regional Islamist movements that Saudi and some other Gulf rulers see as a threat to their own family dynasties.

However, with political Islam now on the defensive again after the army-backed overthrow of Mr. Morsi's Muslim Brotherhood-allied government in Egypt, Saudi Arabia's conservative, security-focused views for the Arab world are now on the ascent.

The Saudis have pledged well over $10 billion to prop up favored Arab governments post-Arab Spring.

Meanwhile, in Turkey, an Islamically oriented government that for years won admiration for a pragmatic, business-friendly regime, has alienated many former supporters with what are seen as bungled or overly aggressive policies. So has Qatar, which, countering Saudi Arabia, backed political Islam.

U.S. President Barack Obama meets with King Abdullah of Saudi Arabia in the Oval Office of the White House in Washington on June 29, 2010. REUTERS

On Sunday, a prominent Saudi royal, Prince Alwaleed bin Talal, announced via Twitter and a news release that he had fired Tareq al Suwaidan, a general manager of one of his television stations, after the "revelation" that the man belonged to the "Brotherhood terrorist movement."

The man's status as a leader of the Kuwaiti Muslim Brotherhood had long been noted on his Wikipedia entry, on YouTube, and elsewhere.

The move by the prince, whose large business holdings include shares in News Corp, which owns The Wall Street Journal, could signal a further crackdown on Islamic activists within the Saudi kingdom.

Influential Saudi clerics including Salman al Odah, who earlier this year challenged the government on Twitter to increase freedoms and transparency, have posted condemnations of the violence in Egypt on Twitter and Facebook.

Write to Ellen Knickmeyer at ellen.knickmeyer@dowjones.com