AMNA NAWAZ: One of the largest financial backers and supporters of Hamas is Iran.

And although the Biden administration has said no intelligence shows that Iran approved or green-lit the October 7 Hamas attacks on Israel, the relationship between Iran and Hamas is strong and lasting.

Our special correspondent in Tehran Reza Sayah sat down with the top Hamas representative to Iran for a rare interview.

REZA SAYAH: At the annual government-organized rally in Tehran this week to mark the anniversary of the 1979 seizing of the U.S. Embassy, the chant that has long echoed in the Islamic Republic, "Death to America."

And among the featured speakers leading those chants in fluent Farsi was a man who is neither Iranian nor a follower of Shia Islam, Iran's state religion.

Where did you learn how to speak Farsi?

KHALED AL-QADDUMI, Hamas Representative in Iran: I have been in Iran for 10 or 12 years.

REZA SAYAH: For much of those 12 years, Kuwaiti-born Palestinian Khaled Al-Qaddumi has served as the permanent representative of Hamas in Tehran, a post that underscores the Islamic Republic's close ties with the Sunni Islamist and militant movement designated by the U.S., the European Union and others as a terrorist organization.

Many people don't know that Hamas has an office here.

What does your day look like?

What do you do?

KHALED AL-QADDUMI: Yes.

Well, I mean, we have a representation office over here.

We deal with all decision-makers, organizations over here.

We talk to the people.

We work with them in cultural activities, political activities.

Iran is a big brother to us.

They have supported the Palestinian issue even much before creation of Hamas.

They extended their support to the whole Palestinian from the beginning, since the beginning.

REZA SAYAH: Relations between Iran and Hamas frayed during the Syrian war, when Hamas backed its fellow Sunni Syrian rebels and stood against Tehran's Shia militias and Syrian President Bashar al-Assad.

In 2017, the two reconciled under the shared view that Israel is not a legitimate state.

Today, Hamas officials openly praise Iran's military and financial support that, according to the U.S. State Department, has reached $100 million a year.

Soon after the October 7 attacks, there was speculation in Washington and beyond that Tehran helped plot the assault that Hamas calls the Al-Aqsa Flood.

Tehran and Hamas deny the Islamic Republic was involved.

Many believe that Hamas would not launch this attack without support, without a green light.

Who gave Hamas the green light?

KHALED AL-QADDUMI: That's a very strange question.

Hamas is a deep-rooted organization in the Palestinian arena.

We have gained the trust of our people in the field.

Of course, we defended our people a long time ago in the First Intifada, Second Intifada.

The Al-Aqsa Flood was a pure, transparent, signed Palestinian operation.

REZA SAYAH: Did you know what was going to happen?

KHALED AL-QADDUMI: No.

Many of my seniors, they didn't.

In general lines, we are in coordination with Iran and Hezbollah, with the components of the resistance axis.

REZA SAYAH: Increasingly, Russia is emerging as another key supporter of Hamas.

Late last month, Moscow hosted delegates from Hamas and the Islamic Republic.

Moscow says the meeting was to discuss the release of Russian hostages.

But some speculate that Russia has other motivations.

There's a number of geopolitical conflicts.

One of them is the Russian-Ukrainian conflict.

Russia is one of your supporters.

Some are starting to say, perhaps Russia wouldn't mind delivering a blow to the United States, to Washington.

KHALED AL-QADDUMI: I mean, I need to remind you over here and your audience that, as Israel have friends, we have also friends.

I mean, I feel that it's the duty of our friends, allies and the freedom, rational voices in the world to support our struggle against colonial powers of Israeli.

So, if we say that Russia and President Putin is supporting us, that is very much rational and logic.

REZA SAYAH: So did Russia have any role?

(CROSSTALK) KHALED AL-QADDUMI: No, no, no.

But we were a couple of days ago over there in Moscow, and we received good reception from them with the authorities over there, and we chatted over many, many things.

I mean, they were very warm.

And they are friends.

REZA SAYAH: These days, Qaddumi gets plenty of warm receptions at government-organized events in Tehran, where he criticizes the Israeli government's bombing campaign of Gaza, its occupation of Palestinian land, and defends the October 7 terror attacks that killed more than 1,000 civilians in Israeli towns bordering Gaza.

You say the occupation and the illegal settlements are the root cause of this conflict.

You say Israel is to blame, but I have to ask you, how did the attacks of October 7 help resolve these issues?

KHALED AL-QADDUMI: See, the attack of 7 of October is a very reaction to the big action of occupation.

Sometimes, you do it with a stone, and, sometimes, you do it with effective rockets that's shaken the Israeli army.

And now you have awakened the international community that Palestine is not to be wasted.

And then, for us, when the so-called peaceful solution is exhausted and the peace process did -- failed, and we are in a cul-de-sac, then the -- it is a legitimate, integral right to the people who are living under occupation to defend themselves with all possible means.

Hence, nobody should ask us why we have started this thing.

REZA SAYAH: You believe the media oftentimes dehumanizes Hamas, sometimes dehumanizes the Palestinian people.

And here you have the October 7 attacks, where innocent civilians were attacked.

How do you reconcile that?

KHALED AL-QADDUMI: Well, see, when you talk to me, it doesn't mean that you agree to what I am saying.

So, this is what I am simply asking.

REZA SAYAH: What are you asking?

You want to be heard.

KHALED AL-QADDUMI: Yes.

REZA SAYAH: So I'm listening to you.

I'm here.

You're talking to an American audience, who've seen some horrific images.

Tell the American people what Hamas plans to do to end the fighting, to end the bloodshed.

KHALED AL-QADDUMI: Hamas is looking for the justice, and they are adapting a right... REZA SAYAH: Be specific.

What can you do right now?

KHALED AL-QADDUMI: And I'm telling you, I'm telling you, we are adapting the right which has been granted for the masses, for the nations.

REZA SAYAH: The right to fight back.

KHALED AL-QADDUMI: The right to fight back, the right to defend ourselves.

REZA SAYAH: So you're suggesting the conflict is going to continue?

KHALED AL-QADDUMI: Unless and until we are getting our own rights.

REZA SAYAH: Be specific.

KHALED AL-QADDUMI: Yes.

REZA SAYAH: What do you want to happen immediately?

KHALED AL-QADDUMI: Lifting the siege, releasing 7,000-plus prisoners.

They are our heroes.

They are not criminals.

Many of them, they are within -- without any fair trial.

Finishing the occupation and many things.

We can draft it.

But I'm telling you, I mean, you are asking something which is not fair, because it's always me as... (CROSSTALK) REZA SAYAH: No, no, no, it's not.

I have you now.

I have you now.

So, I'm just... KHALED AL-QADDUMI: I am the victim.

The bottom line, that Palestinians are living under occupation.

We have two ways, only two ways.

Either international community make Israel pay the tax of independence of the Palestinians, or we will do it our own self.

REZA SAYAH: What Hamas decides to do from here is a daunting open question.

What is clear is that Hamas is committed to an unprecedented level of violence in its war with Israel, and standing firmly behind them is the Islamic Republic of Iran.

For the "PBS NewsHour," I'm Reza Sayah in Tehran.