After the failed agreement in the UN Security Council on the continuation of humanitarian aid for people in need in Syria, aid organizations are sounding the alarm.

The worst hunger crisis since the conflict began more than 11 years ago is threatening the lives of millions of people, said International Rescue Committee (IRC) President David Miliband.

The Syria Director of German Agro Action, Else Kirk, warned at the weekend that a new UN resolution is essential so that millions of people can receive important humanitarian aid.

The Secretary General of the Norwegian Refugee Council (NRC), Jan Egeland, tweeted that without the green light for cross-border aid, the suffering of the already exhausted population will be endless.

He went on to write: "Incredibly irresponsible Russian veto of Norwegian/Irish resolution." Aid organization Save the Children warned that without cross-border aid, hundreds of thousands of children would not know where their next meal was coming from.

The UN Security Council was initially unable to agree on the continuation of cross-border humanitarian aid for millions of people in the north-west of the civil war-torn country.

At one meeting, Russia vetoed a draft resolution drafted by Ireland and Norway to continue the important relief mechanism for another year.

Moscow wants to use this to strengthen the Assad regime's grip on UN aid and also to further blur the line between humanitarian aid and reconstruction aid.

A counter-resolution by Russia, according to which the Bab al-Hawa border crossing in northwestern Syria should initially only remain open for another six months, was not approved either.

Around 4.4 million refugees in northern Syria

The background is a UN resolution that has existed since 2014 and expires on Sunday as scheduled.

The regulation allows the United Nations to bring important relief supplies through border crossings to parts of the civil war country that are not controlled by the government.

Russia, which supports the Syrian leadership, has repeatedly signaled that it also wants to close the last of what were once four border crossings - Bab al-Hawa in the north-west.

Then UN aid could only get to Syria via the government in Damascus.

According to the UN, around 4.4 million people live in north-west Syria.

More than half of them are displaced, many of whom have been living in camps for years.

4.1 million people in the region are in need of humanitarian assistance.

Syria is not only suffering from the consequences of the civil war, but also from a severe economic crisis.

According to UN estimates, more than 90 percent of people live below the poverty line.

Millions are short of food.