A report from the International Atomic Energy Agency (IAEA) has shown that Iran continues to move closer to nuclear weapons capability despite resolutions from the U.N. Security Council.

The report, which was released on Monday, revealed that Iran now has a 2.8 ton stockpile of low-enriched uranium, which, if enriched further, is enough to create three nuclear bombs.

The report also said that Iran has at least 22 kilograms of uranium enriched to 20 percent purity - a major technical hurdle on the way to making weapons-grade uranium. Weapons-grade uranium must be enriched to 90 percent purity, which is a relatively easy process, according to experts.

"Based on an overall analysis undertaken by the agency of all the information available to it, the agency remains concerned about the possible existence in Iran of past or current undisclosed nuclear-related activities involving military-related organizations, including activities related to the development of a nuclear payload for a missile," the report said.

The IAEA also rebuked Iran for banning two of its inspectors from the country in June after they reported about undisclosed nuclear activity.

"Iran has not provided the necessary cooperation to permit the agency to confirm that all nuclear material in Iran is in peaceful activities," they said.

On Monday, White House spokesman Tommy Vietor called the report "troubling" and said it was proof that Iran is planning to build nuclear weapons.

"The IAEA's latest report on Iran again demonstrates that Iran is refusing to comply with its international nuclear obligations, and continues its effort to expand its nuclear program and move closer to a nuclear weapons capability."

Iran has denied the claims and says it plans to use the uranium for peaceful purposes, such as fueling civilian power plants or a medical research reactor.

The United Nations, however, has said that Iran has failed to give sufficient evidence of the peaceful nature of their nuclear program.

In June, the U.N. imposed its fourth set of sanctions on Iran which allow for foreign states to inspect Iranian cargo ships among other things.

The same month, the U.N. scheduled a conference for 2012 that would work towards making the Middle East a nuclear weapons-free zone, although Iran's defiance and issues over Israel's nuclear program have threatened the success of the talks.

The IAEA has been under pressure from its Arab member states to put Israel's nuclear program, which is considered the only weapons-grade one in the Middle East, under international control.

Israel has said they will not comply with such a measure, calling it a tactic to divert attention away from nuclear programs in Iran and Syria.

Israel is one of three U.N. member states, including India and Pakistan, that has not signed the Nuclear Non-Proliferation Treaty (NPT) – a measure introduced in 1970 that limits the spread of nuclear weapons. North Korea withdrew from the NPT in 2003 following accusations from the U.S. that they were building nuclear weapons.