White House Meets on Syria Crisis, Fragile Cease-Fire

— -- The U.S. Secretary of State and the Secretary of Defense are set to meet with President Obama in the White House situation room this afternoon to discuss the war in Syria and the fight against ISIS.

This meeting of the national security team comes as the tenuous, U.S. and Russian brokered cease-fire in Syria enters its fifth day, and although the country has seen a great reduction in violence, humanitarian aid deliveries have yet to occur, according to the White House.

Much of the cease-fire negotiations centered around the guarantee of those deliveries -- and without them the agreement becomes increasingly unstable.

Kerry spoke by phone today with his Russian counterpart, Foreign Minister Sergei Lavrov, asking him to use his influence to encourage Syrian President Bashar al-Assad to allow access by the United Nations humanitarian convoys, according to State Department spokesman John Kirby. Kerry also told Lavrov that plans for a joint military operation between the U.S. and Russia will not begin until that aid is delivered to those opposition held areas.

White House spokesman Josh Earnest took a much more accusatory tone today, squarely blaming the Russians and the Assad regime for the lack of aid deliveries.

"The Russians are the ones that are party to this agreement. They are the ones that have made a commitment to use their influence with the Assad regime to reduce the violence and allow humanitarian access," Earnest said. "Either the Russians are unable to live up to the agreement -- maybe they don't have the juice and influence that they claim to have and that we all thought they had -- or maybe they are just unwilling. But in either case it means that they are not living up to the terms of the arrangement."

The agreement stuck in Geneva between the U.S. and Russia calls for the establishment of a "Joint Implementation Center" after seven days of sustained calm and aid deliveries, a place where Russia and the U.S. would share military intelligence and conduct operations against ISIS.

It appears, given the guidelines, that the seven-day clock has yet to start counting down. The State Department said earlier this week it would not talk publicly about the complexity of that timeline.

Meanwhile, that aid delivery hinges on one contested choke point into the rebel-held areas of Aleppo, Syria, a highway called Castello Road. It's one of the only remaining transit points into the devastated city of Aleppo that can accommodate the deliveries. Regime and rebel forces, both reluctant to back off from hard fought gains, are not backing off from their positions, making it too dangerous to send in the trucks.

The Syrian army has said it will pull back its forces as soon as the rebels are willing to do the same.

Elsewhere in northern Syria, several dozen U.S. Special Forces members have begun to advise, assist and accompany Turkish rebel groups fighting ISIS, according to a U.S. official. They'll be fighting alongside Turkish special forces and vetted Syrian opposition forces in an effort to take the town of Dabiq from ISIS, part of a greater mission to rid the Turkish border region of extremists.