The sanctions committee gave details of two recent incidents in which vessels carrying arms-related materiel from Iran to Syria were intercepted by UN member states.
Last month, Iran and Syria rejected Israeli accusations that a ship it had intercepted in the Mediterranean was carrying arms from Iran for the Lebanese group, Hezbollah.
Thursday's report also dealt with recent revelations of an undeclared uranium enrichment plant near the city of Qom and Iran's recent declaration that it intends to build 10 more enrichment plants.
Iran's UN Mission called the assertions "baseless and unfounded" in a statement, saying Iran remains committed to the nuclear Non-Proliferation Treaty (NPT) and the International Atomic Energy Agency's Comprehensive Safeguards Agreement.
"Iran has repeatedly, clearly expressed its position that nuclear weapons have no place in its military doctrine," the statement said.
"Therefore, Iran's nuclear activities are, and have always been, for peaceful purposes, and thus pose no threat whatsoever to the other states' security."
Susan Rice, the United States' UN ambassador, said that while the US remained committed to engaging Iran and reaching a diplomatic solution, "the time is short".
"Engagement cannot be a one-way street. Iran must conclusively demonstrate a similar willingness to engage constructively and address the serious issues associated with its nuclear programme," Rice said.
"Should Iran continue to fail to meet its obligations, the international community will have to consider further actions."
All three ambassadors expressed disappointment that Iran had failed to accept a proposal backed by International Atomic Energy Agency (IAEA) that would have allowed it to export its uranium for enrichment abroad and have it returned in the form of fuel for nuclear reactors.
'Patience and restraint'
The proposal was intended to prevent Iran from "weaponising" the uranium, something Tehran claims it has no desire to do.
Mark Grant, the UK's ambassador to the UN, said: "Iran has taken every opportunity to delay and protract our efforts to reach agreement on this issue. The only reasonable conclusion that can be drawn is that their responses are calculated to buy time and to try to divide the international community."
UN ambassadors from China and Russia, however, urged more time for diplomatic efforts in relation to Iran's nuclear programme.
"There is still space for the diplomatic efforts of the international community to resume talks. It may require more time and patience on all parts," China's Zhang Yesui said.
Vitaly Churkin, Russia's UN ambassador, urged "patience" and "restraint".
The UN Security Council has so far adopted three sets of sanctions against Iran over its under fire nuclear programme.