Instead of alleviating the misery of more than nine million Syrians who need urgent assistance, the humanitarian crisis has worsened since Resolution 2139 was adopted in February.
Amos said all parties to the conflict were guilty of violations, according to a diplomat who attended the closed door briefing.
Only 15 per cent of locations identified as in need of aid had been reached and only 12 per cent of Syrians in "hard to reach areas" had received assistance, Amos told the Council.
Amos demanded security guarantees so that aid convoys could cross conflict and border lines, telling the 15-member Council that there was no time to wait for travel permits.
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The UN estimates that 3.5 million people in Syria live in hard to reach areas and 250,000 are besieged, the majority by Syrian security forces but some also by armed opposition groups.
It is Amos's second briefing since the resolution was passed and comes a week after UN chief Ban Ki-moon said aid access had not improved, blaming both sides but singling out the government.
But to introduce targeted sanctions a new resolution would be needed, which Russia, a key ally of Damascus, would veto.
Russia and China have vetoed three previous Security Council resolutions on Syria since the conflict began three years ago.
Russian ambassador Vitaly Churkin told the Council that the main obstacles were "terrorist activities," diplomats said.
French ambassador Gerard Araud accused Churkin of parroting the words of the Syrian government and Russia of ignoring reality.
To pressure Damascus and embarras Moscow, Western powers want to refer Syria to the International Criminal Court for war crimes.