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 BidenJoseph (Joe) Robinette BidenTrump has lost support from male voters since shutdown, analysis shows Biden-Abrams ticket would be a genius media move The Hill's 12:30 Report: Trump attacks on McCain rattle GOP senators 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 CottonThomas (Tom) Bryant CottonSenate rejects border declaration in major rebuke of Trump Hillicon Valley: Doctors press tech to crack down on anti-vax content | Facebook, Instagram suffer widespread outages | Spotify hits Apple with antitrust complaint | FCC rejects calls to delay 5G auction Senate votes to confirm Neomi Rao to appeals court MORE (R-Ark.) wrote in a letter to Maliki in March. 

On Tuesday, Sen. John McCainJohn Sidney McCainCrenshaw to Trump: 'Stop talking about McCain' Vietnam Veterans of America 'chagrined' Trump won't let McCain 'rest in peace' National Cathedral says Trump didn't need to give 'approval' for McCain funeral MORE (R-Ariz.) along with Senate Armed Services Committee chief Carl LevinCarl Milton LevinListen, learn and lead: Congressional newcomers should leave the extremist tactics at home House Democrats poised to set a dangerous precedent with president’s tax returns The Hill's 12:30 Report — Sponsored by Delta Air Lines — White House to 'temporarily reinstate' Acosta's press pass after judge issues order | Graham to take over Judiciary panel | Hand recount for Florida Senate race MORE (D-Mich.), ranking member Jim InhofeJames (Jim) Mountain InhofeThe Hill's Morning Report - Dems look to rebuild 'blue wall' Funding caps, border wall set stage for defense budget battle Trump's claims of defeating ISIS roil Congress 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 (Bob) MenendezThe Hill's 12:30 Report: Manafort sentenced to total of 7.5 years in prison Acting Defense chief calls Graham an 'ally' after tense exchange William Barr is right man for the times MORE (D-NJ) and Bob CorkerRobert (Bob) Phillips CorkerTrump keeps tight grip on GOP Brexit and exit: A transatlantic comparison Sasse’s jabs at Trump spark talk of primary challenger 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.