US President Donald Trump and Ukrainian president Volodymyr Zelenskyy will be meeting at the White House to discuss a deal that could either be "a great success or quietly fade away".
Mr Trump wants to "recoup" US aid money sent to help Ukraine defend itself against Russian invaders, while Mr Zelenskyy wants security assurances for his country.
In the lead-up to this, Mr Trump has discussed "major economic development" with Russian President Vladimir Putin and called Mr Zelenskyy a "dictator".
So, it could be tense when the two leaders get together.
When are Trump and Zelenskyy meeting?
On Friday, local time.
We're expecting it to be on Friday night here in Australia.
Why are Trump and Zelenskyy meeting?
They're discussing a deal that would give the US access to a portion of Ukraine's rare earth minerals.
Rare earth minerals or metal is a catch-all term for a group of 17 elements including 15 silvery-white metals plus scandium and yttrium.
In the Ukrainian context, we're talking about minerals including graphite, uranium, titanium and lithium.
The deal would give the US access to half the revenue generated by Ukraine's natural resources in exchange for US support.
Here's what Mr Trump said about it on Tuesday:
"This deal, which is an 'Economic Partnership', will ensure the American people recoup the tens of billions of dollars and military equipment sent to Ukraine, while also helping Ukraine’s economy grow as this brutal and savage war comes to an end."
But it's not just about sharing minerals.
For Ukraine, it's also about what the US will do to help in the ongoing war with Russia.
Mr Zelenskyy said a framework of an economic deal had been reached but it didn't have anything about US security guarantees yet.
"This agreement may either be a great success or quietly fade away," Mr Zelenskyy said.
"And I believe success depends on our conversation with President Trump."
Whose idea was it to exchange minerals?
Mr Zelenskyy floated the idea in a "victory plan" presented to Ukraine's allies in October.
He proposed a special agreement for strategic partners, where Ukraine would exchange critical resources for protection and investment:
"This involves natural resources and critical metals worth trillions of US dollars, including uranium, titanium, lithium, graphite, and other strategically valuable resources, which are a significant advantage in global competition."
How much does Ukraine have?
It's unclear how much of these minerals Ukraine actually has.
Ukraine's Deputy Environmental Protection and Natural Resources Minister Svetlana Grinchuk told the UN in 2022 that the nation had "about 5 per cent" of the planet's "critical raw materials"
But there are questions about the reliability of numbers currently available.
"Unfortunately, there is no modern assessment [of rare earth reserves in Ukraine]," Ukrainian Geological Survey's former director Roman Opimakh told S&P Global.
"And there is still restriction to make this information public."
"Existing mapping was done 30 to 60 years ago by the Soviet Union and relies on old exploration methods," a report from US-based research organisation Center for Strategic and International Studies (CSIS) says.
Specific details about the size of lithium, titanium and uranium deposits in Ukraine are classified.
Many ore deposits for other minerals haven't been fully explored yet, the Ukrainian Geograpical Survey said in an investor pitch on the government's website.
It also admitted that data for advertised investment opportunities comes from "legacy" geological reports.
Geologists, including at France's Bureau of Geological and Mining Research (BRGM), found more than 100 resources, including iron, manganese and uranium, in a study of Ukraine published in 2023.
But further exploration and development would require heavy investment, BRGM said.
How would the US get these minerals?
It remains unclear how the Trump administration might actually get access to Ukraine's rare earth minerals.
This might be difficult, because mining analysts and economists say Ukraine currently has no commercially operational rare earth mines, Reuters reports.
Such projects would take years to develop, cost a lot of money and need mining investors.
And attracting investors has already proven to be a difficult task for the Ukraine, whose Geological Survey website already pitches heavily to mining investors.
Ukrainian think-tanks We Build Ukraine and the National Institute of Strategic Studies estimate about 40 per cent of Ukraine's metal resources are now under Russian occupation.
Industry experts say it would be difficult for Ukraine and the US to attract mining investments, given the security risks.
And even once the conflict ends, there could be long-term impacts that may dissuade investors.
"The war has wiped out essential infrastructure," CSIS says.
"There will need to be a significant build-out of energy infrastructure for mineral exploration or production can commence."
Does this mean the US will defend Ukraine?
Mr Trump says the US will not directly provide any concrete security guarantees.
"I'm not going to make security guarantees beyond … very much. We're going to have Europe do that," he said on Wednesday.
But he didn't go into detail about what that "Europe" remark meant.
Meanwhile, Mr Zelenskyy said his talks with the US would stress the importance of obtaining security guarantees to ensure "Russia never again destroys the lives of other nations".
"It is crucial for me, and all of us in the world, that American aid is not halted.
"Strength is essential on the path to peace."
While agreement drafts have been circulating in the build-up to the meeting, the terms could change before both parties officially sign off on the deal.
Do Trump and Zelenskyy get along?
Last week, Mr Trump called Mr Zelenskyy a "dictator" who is doing a "terrible job" leading Ukraine in a social media post — here's just a snippet of that:
"He refuses to have elections, is very low in Ukrainian polls, and the only thing he was good at was playing Biden 'like a fiddle'.
"A dictator without elections, Zelenskyy better move fast or he is not going to have a country left."
If Ukraine wasn't still warring with Russia, Ukrainians would have had a presidential vote at the end of last year.
But under the Ukrainian constitution, elections are legally suspended while it defends itself so Mr Zelenskyy remains president.
Mr Trump and Mr Zelenskyy's history goes back to the American's first term as president in 2019.
Back then, Mr Trump allegedly pressured Mr Zelensky to investigate Joe Biden's son Hunter Biden's past ties with Ukraine in a now infamous phone call.
The allegation was that Mr Trump — who was withholding $US391 million in aid from Ukraine at the time — was extorting Mr Zelenskyy to dig up dirt about the Biden camp to give him an edge in the 2020 presidential election.
This led to his impeachment in December 2019 (Mr Trump's second impeachment was in 2021 after the insurrection at the Capitol building) and while it didn't mean he was kicked out of office because the Senate acquitted him, it certainly wasn't a pleasant experience.
What does the US say about Russia?
The US and Russia have been in talks lately, with Mr Trump speaking to Mr Putin in a phone call earlier this month.
Around this time, the US Defence Secretary Pete Hegseth said that restoring Ukraine's pre-2014 border — that is, Russia ceding control over Crimea — was "unrealistic".
This was a big shift in US policy on the war.
Mr Hegseth also ruled out Ukraine being granted membership of the North Atlantic Treaty Ogranisation (NATO) — something Mr Zelenskyy wants for Ukraine as it could compel member countries to retaliate against attacks on the besieged nation.
Trump's Secretary of State Marco Rubio met with Russian counterparts last week, saying "extraordinary opportunities" could come out of a peace deal:
"Should this conflict come to an acceptable end, the incredible opportunities that exist to partner with the Russians, geo-politically on issues of common interest, and frankly economically on issues that hopefully will be good for the world and will also improve our relations in the long term between these two important countries."
He said that "everyone involved in that conflict has to be OK with" any potential peace deal, but didn't go into about whether that would mean Russia giving up annexed Ukrainian territory.
And earlier this week, the US sided with Russia in voting against a United Nations (UN) resolution on the war — a move regarded as another major shift in the US policy on the war.
The US voted down a resolution blaming Russia for the war in Ukraine and demanding the immediate withdrawal of its troops.
However, 93 other countries — including Australia and most of Europe — voted in favour of the resolution and it was adopted by General Assembly.
On that same day, Mr Trump said his talks with Mr Putin were "proceeding very well".
"I am in serious discussions with President Vladimir Putin of Russia concerning the ending of the war, and also major economic development transactions, which will take place between the United States and Russia," he said on social media.
