VIENNA — As the world’s nuclear watchdog, the International Atomic Energy Agency is responsible for ensuring nuclear energy is used for peaceful purposes. That has rarely been easy.

Established as an agency of the United Nations in 1957, the IAEA has been at the center of one of the world’s biggest nonproliferation crises — in Iran, where its inspectors are monitoring the 2015 nuclear deal. They are barred from the other, in North Korea, which kicked the agency out in 2009.

Director-General Yukiya Amano, a Japanese diplomat, has led the agency since 2009 and was recently elected to a third term. In a recent interview, he defended the IAEA’s inspections program in Iran and said worries over weapons distracted attention from constructive applications of nuclear energy. Here are excerpts from the conversation.

Are you disappointed when critics of the Iran deal question the IAEA’s ability to monitor Iran’s nuclear program?

We are a technical organization and I am discharging my responsibilities based on rules, based on the IAEA standard safeguards practice. We simply keep on working and monitoring and verifying the nuclear-related commitments made by Iran under the [nuclear deal] in an impartial, objective and professional manner. So, whatever happens, we keep on working.

Are you inspecting Iranian military sites?

When we identify the need, we seek access to the locations. We don’t make a difference between civilian and military locations, [but] we don’t discuss details of where we go.

Iranian officials insist that military sites are off-limits, when you’re saying that isn’t the case. Are those comments unhelpful?

We hear many remarks, not only from Iran, but from other countries too. But our job is to analyze the facts. Facts mean nuclear material and facilities related to nuclear material. The function and objective of the IAEA is not to analyze remarks.

The IAEA has produced seven reports on Iran’s compliance with the nuclear deal, but critics say you’re being too soft on Iran and not providing enough details.

The information collected by inspectors must be kept confidential. These people complain that they don’t have information related to Iran, but they don’t have information about Germany, Japan or Kenya either. It’s like a doctor. People go to a doctor with the understanding that he won’t disclose sensitive information.

But you have the discretion to decide what to release. If the Iran inspections are going smoothly, why not disclose more information to respond to your critics?

Discretion means when I have a good reason. It doesn’t mean the director-general can do whatever he likes to do. When there is concern of a violation, and when there is a U.N. resolution, yes. But it is not the practice that some countries ask more and I say, “Let’s give more,” or, “Let’s give less.”

If President Trump puts more pressure on Iran, will IAEA inspectors lose the access they currently enjoy?

It’s very difficult to foresee what will happen. As we are a technical organization ... speculation does not make sense for us. We have cameras, we have [electronic equipment] seals, we have inspectors, so we are factual and impartial and that is our advantage.

What is the IAEA doing in North Korea, where the last inspectors were thrown out in 2009?

We are observing the North Korean nuclear program through satellite imagery and collecting open source information. I decided to establish a small team in August with the objective to enhance our capability to monitor the North Korean nuclear program and enhance our readiness to go back to North Korea. I don’t mean that I see an immediate opportunity. It’s obvious the situation is very serious and grave. Their nuclear program is making progress. Therefore, we need to update the training of our inspectors, procure the necessary equipment and make a verification plan ... so that if we are authorized, we can send our inspectors at short notice.

Nuclear power produces less carbon than fossil fuels. How can it help combat climate change?

The amount of carbon dioxide emissions that the use of nuclear energy can reduce — it’s equivalent to the amount emitted by India or Russia. That is a huge amount. Thirty countries use nuclear power for the time being, and about 30 more are interested. In countries where people feel the effects of climate change, where we need to develop new plant varieties, if we apply gamma rays, we can accelerate plant mutations and identify the right crop varieties that are resistant to disease. Ocean acidification has become a huge problem all over the world, but if you observe radiation coming from isotopes, you can diagnose the health of oceans and that is very helpful to establish the response.

But in your home country, Japan, the 2011 Fukushima Daiichi disaster turned public opinion against nuclear energy. What needs to happen to restore public confidence?

There was a belief in Japan that a serious nuclear accident would not happen. Preparedness and response were not enough. The independence of the regulatory body was not enough. It has been reformed. A lot of measures were taken both in Japan and globally. All the countries that use nuclear power undertook stress tests to review if their plants would withstand severe natural hazards. They have taken measures where needed, and a lot of safety standards have been reviewed and strengthen-ed.

How does the agency promote nuclear power for uses people don’t often consider, such as medicine?

Nuclear technology is very useful to achieve the U.N.’s sustainable development goals, for human health and animal health. Nuclear technology was helpful to diagnose Ebola and Zika, and nuclear medicine and radiotherapy are essential in certain medical areas, such as diagnosing foot-and-mouth disease in cattle. Just recently, we organized a seminar on how nuclear technology can diagnose early symptoms of Alzheimer’s disease. It allows us to look inside the human body with precision.

Is it a challenge to focus attention on those issues, when the world is worried about weapons programs?

We should pay maximum attention so that nuclear materials are not used for weapons purposes. That is our basic purpose. We need to tell the public that nuclear energy can be very useful and can make a huge difference for the lives of ordinary people.