This week, US President Donald Trump, Ukrainian President Volodymyr Zelenskyy and seven other European leaders arrived at the White House to discuss a possible peace deal for Ukraine, following a meeting between Mr Trump and Russian President Vladimir Putin last Friday.
Outside official peace talks, however, the spotlight shifted to the first ladies of the United States and Ukraine, with each penning a letter pleading for empathy and an end to the conflict.
Here's what we know about the letters and how first ladies in the past have used soft power to speak out.
What we know about the letters
While meeting with Russian President Vladimir Putin in Alaska, Donald Trump handed him a letter from the first lady.
Melania Trump's "peace letter" highlighted the impact of war on children.
The letter did not specifically name Ukraine, which Putin's forces invaded in 2022.
But it did implore him to think of children and "an innocence which stands above geography, government, and ideology".
[tweet bondi]The gesture apparently inspired Ukraine's first lady, Olena Zelenska, to do something similar.
In his Oval Office meeting with Mr Trump, Mr Zelenskyy delivered a letter written by his wife.
"It's not to you, it's to your wife," he told the US president.
We don't know word for word what Ms Zelenska's letter said as it wasn't made public.
However, we do know that it expressed gratitude to Melania for her own letter to Mr Putin calling for the protection of children.
Jessica Genauer, a senior lecturer in international relations at Flinders University, says Ms Zelenska's objective was most likely to keep Ukraine in the focus and to create a connection with the US first lady.
"Ukraine understands that developing god-friendly relations with President Trump will be critical to ensuring an outcome in the war with Russia that meets some of Ukraine's interests," Dr Genauer told ABC News.
"Trump has mentioned in the past that Melania has influenced his perspective on the war in Ukraine."
Mr Zelenskyy praised Melania "for her attention to one of the most painful and difficult issues of this war", adding "we deeply appreciate her compassion".
He continued: "Her voice matters, and her care gives strength to this cause".
The Ukrainian government says around 19,500 children have been deported and/or forcibly removed from their homes to Russia or Russia-occupied territories.
Off the back of Melania's letter, European Commission President Ursula von der Leyen and UK Prime Minister Keir Starmer both raised the issue of stolen children during the summit.
"As a mother and grandmother, every single child has to go back to their family," Ms von der Leyen said.
"This should be one of our main priorities also in this negotiation, to make sure the children come back to Ukraine, to their families."
First ladies have long tradition of speaking out
Throughout history, first ladies have been designated with traditional female roles, from planning the menu at state dinners to discussing family-friendly issues like literacy.
But they also have a long tradition of speaking out on humanitarian and political issues, Dr Genauer said.
"A first lady taking a role in humanitarian issues is not unprecedented," she said.
"Advocating for humanitarian issues is often considered a role that transcends political boundaries."
During her first year in the White House in 1989, Barbara Bush visited babies with AIDS.
In 2018, former first lady Laura Bush wrote an opinion piece in The Washington Post that expressed her sadness and disappointment that children were being separated from their parents at the Mexican border.
The next day, Michelle Obama backed her up on Twitter. Rosalynn Carter also chimed in, releasing a statement against the "practice and policy" of "removing children from their parents' care".
During the Russia-Ukraine war, Ms Zelenska used her new-found platform as first lady to drum up support for Ukrainians fleeing the war.
"Most Ukrainians saw Olena Zelenska just as the wife of the comedian who was their president. But now they are comparing her with (former US first lady) Michelle Obama," close friend Ievgen Klopotenko told The Telegraph in 2022.
She shared almost daily posts with her 2.7 million Instagram followers, detailing the realities of war and calling for help on the humanitarian front from diplomats and world leaders.
France's first lady Brigitte Macron was among the first to respond, helping to secure the safe passage of 20 children out of Ukraine to France in order to safely continue their cancer treatment.
However, Dr Genauer says a first lady sending a letter to a president of another country currently at war is unusual.
While she believes Melania's objective was to influence Mr Putin to return Ukrainian children or agree to a ceasefire, it's unlikely the letter will have a "significant impact on Putin and his approach to the war in Ukraine".
What role does soft power play?
Here's the definition of soft power, according to an Australian Government foreign policy white paper:
The ability to influence the behaviour or thinking of others through the power of attraction and ideas rather than coerce.
Dr Genauer says Ms Zelenska's letter to Melania represents an attempt to draw on the levers of soft power to increase the chance that the current US administration will support Ukraine in any future peace deal with Russia.
"The exchange of letters between first ladies is a way to build a positive relationship and emphasise shared values, which are core to soft power," she said.
"Since the start of Russia's full-scale invasion of Ukraine, President Zelenskyy has also focused on consolidating Ukraine's soft power by strengthening his countries relationships and shared values with partners around the world.
"However, it remains to be seen whether Melania Trump will respond to Olena Zelenska's letter with one of her own."
Without ever running for office, first ladies wield a soft power that can make them even more popular than their husbands.
In August 1979, Rosalynn Carter's approval rating stood at 59 per cent compared to her husband's 32 per cent rating.
A CNN poll taken in May 2018, during Donald Trump's first term as president, found 57 per cent of Americans approved of Melania, compared to her husband's 43 per cent.
