Iraq ? Iraqi politicians allied with militant Shiite cleric Muqtada al-Sadr threatened Friday to resign from the government if Prime Minister Nouri al-Maliki meets next week with President Bush, adding to the pressure on an embattled premier who appears unable to halt his nation’s plunge into full-fledged civil war.

Bush aides in Washington said the meeting scheduled for Wednesday in neighboring Jordan would continue as planned, although officials in al-Maliki’s office hadn’t issued a public response by midnight Friday in Baghdad.

Neither Iraq’s political leaders, Iraqi government forces nor U.S. troops have been capable of securing the capital, despite curfews, increased checkpoints and more frequent patrols, and it isn’t clear what could halt the escalating violence.

Describing Bush as “the killer of Iraqi people,” politicians aligned with al-Sadr repeated their demand for the withdrawal of U.S. troops and said Iraqi officials should sever all ties with the United States.

Al-Sadr’s allies are the backbone of al-Maliki’s Cabinet, and even a temporary suspension of their participation would cripple, if not topple, Iraq’s fragile U.S.-backed government.