Award-winning actor and celebrity activist Sean Penn has put aside his political differences with key US talk show hosts to advocate for the people of Ukraine, as the country continues to suffer countless deaths and destruction of entire towns after Russia invaded their sovereign country last month.

In emotional across-the-desk discussions with conservative Fox News and MSNBC on April 5 after his weeks-long stay in Ukraine, Penn, 61, wearing an Army-green windcheater, issued a heartfelt message to Americans across the country.

“These people are fighting for the very dreams and aspirations of all of us Americans,” he told New-York based Fox News‘ Hannity host and long-time adversary Sean Hannity.

Penn, who co-founded crisis response organisation CORE in 2010 after the Haitian earthquake, has been in neighbouring Poland helping thousands of refugees.

He was also in Ukraine before war broke out in November, and in mid-February, filming a documentary with Prime Minister Volodymyr Zelensky – chats were via Zoom until they met face to face a day before the invasion on February 24.

He has been on the ground embedded with troops and eventually was forced to abandon his car and walk to the Polish border, all the time witnessing the atrocities of war.

On his return to the US, Hannity invited a “sceptical” Penn onto his show, and asked him what his initial response was when he picked up the phone.

“Do you remember what you first said to me?” asked Hannity.

Penn responded: “I said, ‘I don’t trust you. There’s a lot of reasons I don’t trust you’.

“I’ve never felt this way about where our country is and what I experienced emotionally in Ukraine. But we have to get on with life.

“We all talk about how … divided things are here. But when you step into a country of such incredible unity, you realise what we have all been missing.

“I don’t think I’ve got time to indulge my lack of trust, it becomes a petty thing, as people and babies are being vaporised, and that these people are fighting for the very dreams that are the aspiration of all of us Americans.”

Penn, who was once married to Madonna and dated Charlize Theron, has spent the better part of the past 20 years involved in political and social activism, and a host of humanitarian assignments.

He told Hannity how his relationship with Mr Zelensky developed during the making of the documentary, and meeting him eventually a day before the invasion started when there was a blackout in the city of Kyiv.

“I don’t know that there’s a person on Earth who could know that they were born for such a day, that they could rise to it,” Penn said.

“He’s the face of something that you see in all the Ukrainians we saw and talked to – whether they were in uniform, out of uniform, schoolteachers, even children – this extraordinary courage that’s come up.

“It was in his eyes.

“It is clear to me that the Ukrainians will win this,” he said. “The question is, at what cost?”

Tweet from @CoreResponse

A short time later, just three kilometres away at the Rockefeller Plaza in Manhattan, Penn sat down with MSNBC’s The Last Word with Lawrence O’Donnell.

As Variety reported immediately afterward, it was “somewhat rare for an individual outside of the cable news rotation to make appearances on two different networks on the same night, especially two with traditionally opposing partisan sensibilities”.

Such is Penn’s passion.

He told O’Donnell: “To be in Ukraine and to feel, despite many political differences … but not on this, not on being able to determine their own dreams.

“They look at each other and they say we’re together in a way that is so heartbreaking for an American to experience.

“Your first heartbreak, of course, is for those under fire, the Ukrainians, but very quickly you’re connected to what you’ve been missing and what you’re promised by the dream.

“It’s a horrible moment in so many ways, but it’s an exciting moment in history to follow the lead of the Ukrainians. They are going to win this thing because they’re together.”

Penn said he’s witnessed a country unified under Mr Zelensky’s leadership, as many thousands of his fellow Ukrainians have brutally lost their lives, and many millions have fled to neighbouring countries to escape the Russian onslaught.

“This is leadership that we aspire to. This is freedom of thought and true leadership that is just so moving. It’s the kind of moving that we need to be able to get [to the United States], which is borderline a kind of populist lap dance of a nation at this point,” he said.

“We’ve got to get back on track together and realise that Ukraine, with all its diversity, has a unity we’ve never seen in modern times with the challenge it has.”

With tears in his eyes, Penn was desperate to bring home to the US what will happen next to this country that has won his heart and soul.

In one of his last social media posts before he returned to the US, he was in Poland, and then Lviv, meeting his CORE team, “strategising” with local government officials and NGOs in a bid to scale up programs.

He showed a photo of a little girl in a pink puffer jacket in a Ukrainian refugee shelter near the country’s western border, playing with a bubble blower.

“When we look back on it, what role will we have played in diminishing the dead, maiming, the rapes, the destruction of this country which is going to have so many demands of reconstruction and where will be then?” Penn posted.

“We’ve got to figure out what we’re going to do in supporting them to do that.”