U.N. Secretary-General Ban Ki-moon said in a report Wednesday that parties involved in Syria’s civil war are guilty of “flagrant violations” of international law regarding the delivery of aid, and urged the Security Council to address them.

Ban, along with five other U.N. officials, also said in a separate statement, that an urgent appeal sent to the warring factions in Syria to end the conflict remained unanswered. He added that 3.5 million people in Syria are living in areas under siege without access to medical care and more than 9.3 million people in the country have been affected by the violence that has entered its fourth year.

“None of the parties to the conflict have adhered to the demands of the Council. The Security Council must take action to deal with these flagrant violations of the basic principles of international law,” Ban said in the report, which the council will discuss next week, according to Al Jazeera, adding that the situation in Syria has deteriorated over the past two months.

In February, Ban had asked the council to implement a resolution seeking greater access to aid to the country's people and the15-member council had unanimously approved a resolution demanding rapid, safe and unhindered aid access, including across borders. However, Ban said in his latest statement that the situation in the region made it an “extremely challenging” environment to work in.

The UK, U.S. and France are considering another resolution to initiate disciplinary action against Syrian President Bashar Assad’s administration, which is believed to be blocking the aid, but the resolution is expected to be vetoed by Russia, according to BBC.

"Medical supplies, including life-saving medicines and vaccines, and equipment for the wounded and the sick are commodities privileged throughout the Geneva Conventions. Denying these is arbitrary and unjustified, and a clear violation of international humanitarian law,” Ban said, according to Reuters.

The appeal from Ban and the five U.N. officials Wednesday said that key roads were being blocked by armed men, including the route from Damascus to Aleppo, and that 60 percent of the U.N.'s health centers have been destroyed.

“All too often, humanitarian access to those in need is being denied by all sides. Aerial bombardment, rockets, mortars and other indiscriminate attacks slaughter innocent men, women, and children,” the U.N. officials said in the appeal, according to a statement released by the U.N., and called on all parties to “enable unconditional humanitarian access to all people in need, using all available routes either across lines inside Syria or across its borders.”