White House presses Iraq to block Iranian aid to Syria

 Baghdad must step up its efforts to block Iranian shipments of weapons and aid moving through Iraqi airspace to Syrian forces loyal to embattled President Bashar Assad, the White House said Wednesday. 

"We would like [Iraq] to do more" to rein in or cut off Syrian supply lines running from Tehran, a senior administration official told reporters. 

Specifically, the Obama administration is pressuring Iraqi Prime Minister Nouri al-Maliki to focus on patrolling the air routes used by Iranian forces to smuggle arms and supplies into Syria. 

Iranian supply routes, along with the growing al Qaeda threat in Iraq and Syria, is at the top of the agenda for Maliki's visit to Washington this week. 

The Iraqi delegation met with Vice President Joe BidenJoe BidenBiden boards train home to Delaware after Trump's inauguration Overnight Tech: Meet the key players for Trump on tech | Patent chief staying on | Kerry aide goes to Snapchat | Uber's M settlement Biden's farewell message: Serving as VP has been my 'greatest honor' MORE Wednesday morning, and will meet with congressional leaders later in the day. 

The White House and Congress have repeatedly voiced their concerns over Iraq's ability to block Iranian aid shipments since the beginning of the Syrian civil war three years ago.

"We are greatly disturbed that as the international community works to bring peace to Syria, the Iraqi government is not doing everything in its power to prevent the slaughter of thousands of innocent civilians," Reps. Ted Deutch (D-Fla.) and Tom CottonTom CottonThe Hill's 12:30 Report GOP, Dems hear different things from Trump The Hill's 12:30 Report MORE (R-Ark.) wrote in a letter to Maliki in March. 

On Tuesday, Sen. John McCainJohn McCainMcCain: Trump's withdrawal from TPP a 'serious mistake' Trump signs executive actions on TPP, abortion, federal hiring freeze Rubio to vote for Tillerson MORE (R-Ariz.) along with Senate Armed Services Committee chief Carl LevinCarl LevinObama to preserve torture report in presidential papers 'Nuclear option' for Supreme Court nominees will damage Senate McCain's Supreme Court strategy leads to nuclear Senate MORE (D-Mich.), ranking member Jim InhofeJames InhofeSenate teeing up Mattis waiver Lawmakers play nice at Russia hacking hearing Senate chairman meets Trump’s EPA nominee MORE (R-Okla.) rasied the issue again in a letter to President Obama, ahead of Maliki's visit to Washington. 

"We urge you to make clear to Prime Minister Maliki that the extent of Iran’s malign influence in the Iraqi government is a serious problem in our bilateral relationship, especially for the Congress," according to the letter. 

Senate Foreign Relations heads Sens. Robert MenendezRobert MenendezCarson likely to roll back housing equality rule Live coverage: Tillerson's hearing for State Booker to join Foreign Relations Committee MORE (D-NJ) and Bob CorkerBob CorkerRubio to vote for Tillerson Top Dem comes out against Tillerson ahead of key vote This week: Congressional Republicans prepare to huddle with Trump MORE (R-Tenn.) also co-signed the letter. 

That said, "policing this is extremely difficult . . . [and] its really an ongoing effort" between Washington and Iraq to shut those supply lines down, the White House official said. 

During the bloodiest days of the Iraq War, U.S. and coalition forces were unable to block similar weapons and supplies shipments from Iran to insurgent groups inside the country. 

For its part, Maliki's government argues it does not have the airpower necessary to ward off the Iranian air shipments. 

To that end, Maliki told reporters in Baghdad he will press the White House to accelerate sales of F-16 warplanes and possible sales of unmanned aircraft to Iraq. 

Washington and Baghdad inked a deal in August to provide Iraq's nascent military with the American jets. 

Without those air assets, Baghdad claims its airspace will remain indefensible to Iranian supplies and support.