The US is set to introduce a 30-day ceasefire proposal negotiated with Ukraine to Russia in the coming days.

Trump administration officials are seeing it as a major breakthrough towards the foreign policy goals of a president who campaigned to end the war.

So does it make a ceasefire plausible? And if so, can it end the war after Russia's full-scale invasion three years ago in a just and sustainable way, and on terms that keep the region and the world safe?

Statement: "Ukraine expressed readiness to accept the U.S. proposal to enact an immediate, interim 30-day ceasefire, which can be extended by mutual agreement of the parties, and which is subject to acceptance and concurrent implementation by the Russian Federation. The United States will communicate to Russia that Russian reciprocity is the key to achieving peace."

Analysis: The key word here is "immediate," which doesn't leave any doubt: Trump wants the guns to fall silent now. His sense of urgency, however, has often led to concerns in Europe.

Many fear that rushing the desired outcome without first working out the terms takes the military pressure off Moscow as the invading power and could lead to a truce being exploited.

They argue it empowers the occupying force.

The fear is of ultimately leading Ukraine into an effective surrender. The theory is that Russia - the bigger, more populous and militarily more self-sufficient power - could use a truce without first establishing concessions to consolidate its forces, string out a negotiation process and wait to see what happens politically for Trump during his term while it holds on to everything it seized; and even then try to take more ground, building on its current occupation and potentially using a fracture in the Western alliance to threaten more of Europe.

The process of negotiating terms before a ceasefire in conflicts can be important to ensure the sides convert current military threats into meaningful strategic gains.

Zelensky has previously tried to persuade the Americans that Russian President Vladimir Putin cannot be trusted, evidenced by the fact he broke the European-backed Minsk agreements after seizing Ukrainian territory in 2014.

Trump dismisses these concerns, saying there will be security for Ukraine, but without saying how this will be assured. He has said Putin will be deterred and is in a difficult position with "no choice" but to make a deal for reasons that "only I know".

Rubio said on Tuesday the US delegation had substantive discussions with the Ukrainians on a permanent end to the war, including "what type of guarantees they're going to have for their long-term security and prosperity", but again didn't elaborate.

Statement: "The United States will immediately lift the pause on intelligence sharing and resume security assistance to Ukraine."

Analysis: This is the big win for Zelensky in this agreement and sees US weapons supplies being delivered at a rate of around $2bn (£1.5bn)-worth a month, restored.

Critically, it also means Washington will once again share its intelligence data and satellite pictures with Kyiv, which helps it target Russian positions. The White House said it suspended this aid because it felt Zelensky wasn't "committed" to Trump's peace plan.

The Ukrainian leader had tried to voice his concerns based on some of the reasons above when he was ejected from the Oval Office. His reservations are likely being set aside while he welcomes the agreement in this form - a necessary price to pay to restore US security assistance.

Statement: "Both delegations agreed to name their negotiating teams and immediately begin negotiations toward an enduring peace that provides for Ukraine's long-term security. The United States committed to discussing these specific proposals with representatives from Russia. The Ukrainian delegation reiterated that European partners shall be involved in the peace process."

Analysis: This paragraph is confusing because it's unclear whether it refers to negotiations between Ukraine and the US on establishing any security guarantees for Ukraine, or if it refers to negotiations between Ukraine and Russia to permanently end the war once a ceasefire is under way.

If it is the former, it appears to suggest that Washington and Kyiv will hammer out any decisions on how to back up Ukraine's security and deter Russian breaches of a truce, and the US will then discuss these with Moscow.

But it is all a far cry from the kind of security guarantee Zelensky ultimately wanted, which was membership of Nato, which Trump has said won't happen - a major long-term concession to Moscow's demands.

The paragraph also contains a vague and lukewarm reference to the idea of European peacekeepers, which have been pitched by the UK and France, with the line attributed only to the Ukrainian delegation.

It's notable that the US appears not to be putting its name to this part after Moscow categorically rejected the idea.

Statement: "…both countries' presidents agreed to conclude as soon as possible a comprehensive agreement for developing Ukraine's critical mineral resources to expand Ukraine's economy and guarantee Ukraine's long-term prosperity and security."

Analysis: This was the agreement that never got signed after Zelensky was told to leave the White House last month.

It would give the US a future stake in some of Ukraine's state-owned mineral deposits, as well as oil and gas revenues.

Trump sees it as an effective security guarantee for Ukraine, arguing it would deter Russian re-invasion because American companies would be on the ground.

Opponents point out this is meaningless because US economic presence in Ukraine didn't deter Putin in 2014 or 2022.

Statement: "The Ukrainian delegation reiterated the Ukrainian people's strong gratitude to President Trump…"

Analysis: This is a key line that might help explain Zelenky's rehabilitation in the eyes of the White House.

Vance had castigated him in the Oval Office for not thanking Trump, even though the Ukrainian leader has thanked the US dozens of times for its military support.

Now Trump has an official Ukrainian thank you, on a piece of paper meant to make peace.