The United States reportedly withheld a shipment of $500 million in cash to Iraq from the Federal Reserve Bank of New York to intensify pressure on Baghdad to disarm Iranian-backed Shiite militias and select a nominee for prime minister suitable to the United States, Reuters reported April 22. In addition, the United States suspended some counterterrorism and security cooperation funding, conditioning it on an end to Iraqi militia attacks and increased efforts by Baghdad to disarm them.

After the 2003 U.S. invasion of Iraq, the United States has maintained a system in which profits from Iraqi oil sales are held in accounts in the Federal Reserve Bank of New York, giving Washington financial leverage over Baghdad. On April 17, the United States sanctioned seven Iraqi militia leaders as Specially Designated Global Terrorists. According to the Iraqi constitution, the Shiite Coordination Framework must select a prime minister nominee by April 26 — 15 days after the Iraqi parliament elected a president.