“In order to swiftly deliver humanitarian aid in Syria, the pressure on the [Assad] regime must be stepped up,” presidential spokesperson Ibrahim Kalin told reporters in the capital Ankara.

Kalin held the Assad regime responsible for the failure to implement a cease-fire as well as blocked aid deliveries, calling it "the biggest obstacle."

Kalin also said to date Turkey has distributed $630 million worth of humanitarian aid to the war-torn country.

On Feb. 24, the UN Security Council unanimously adopted Resolution 2401, which called for a cease-fire in Syria -- especially the besieged Eastern Ghouta enclave -- to allow the delivery of humanitarian aid.

Despite the resolution, however, in early March the regime and its allies launched a major ground offensive -- backed by Russian air power -- aimed at capturing opposition-held parts of the district.

Home to some 400,000 residents, the district has remained under a crippling regime siege for the last five years, which has prevented the delivery of badly needed humanitarian aid.