President Trump is set to meet with President Vladimir V. Putin of Russia in Alaska this Friday. The abrupt nature of the summit and Mr. Trump’s penchant for pursuing deals are feeding questions about the potential outcome.

The meeting, arranged in barely a week, will mark a significant policy change for the United States. Washington has largely treated Mr. Putin as a pariah since the Russian invasion of Ukraine in 2022, which has caused hundreds of thousands of deaths and widespread destruction for both countries. The mere fact that an American president is willing to meet is considered a diplomatic victory for the Kremlin.

On Wednesday, President Volodymyr Zelensky of Ukraine joined a phone call between Mr. Trump and European leaders, who said they had hammered out five principles for the negotiations. They included the idea of pursuing a cease-fire first, according to the Ukrainian president.

Given that the meeting will not include a representative from Ukraine, chances of a breakthrough are considered slim. Mr. Trump has said that he would call Mr. Zelensky directly after his talks with Mr. Putin, and that he considered the Alaska summit a prelude to a Putin-Zelensky meeting.

Where is the summit happening?

Mr. Trump will meet Mr. Putin at Joint Base Elmendorf-Richardson in Anchorage on Friday, according to a White House official familiar with the planning.

Karoline Leavitt, the White House press secretary, told reporters during a news briefing on Tuesday that the two men were expected to meet one on one. She described the meeting as a “listening exercise” for Mr. Trump that would give him a better idea of the Russian leader’s plans.

In 2018, Mr. Trump and Mr. Putin met alone, except for interpreters, for more than two hours during a summit held in Helsinki, Finland.

Why is the summit happening now?

Ever since Mr. Trump took office in January, the United States and Russia have repeatedly raised the possibility of a summit between the American president and Mr. Putin.

While the Russian leader has been eager for a meeting, Mr. Putin had balked at taking any concrete steps toward ending the war while he believed that Russia was advancing on the battlefield.

Mr. Trump, initially supportive of Russia and critical of U.S. military aid to Ukraine, held off on a meeting while ending the war appeared impossible. He repeatedly expressed his frustration.

Then, last week, he moved up the deadline for imposing new sanctions or tariffs unless Mr. Putin ended the war. He also raised tariffs on Indian imports to the United States to 50 percent to penalize it for continued imports of Russian oil. With the sanctions deadline looming, the Russians requested a summit.

What does Putin want from a summit?

It is possible that Mr. Putin is using the summit as another stalling tactic, as well as a way to try to improve frayed ties with Washington. He also might seek to discuss issues outside the framework of Ukraine, including economic deals or cooperation in the Arctic.

On a larger scale, the summit corresponds to Mr. Putin’s worldview, that great powers should determine their own spheres of influence, much as Stalin met with President Franklin D. Roosevelt and Prime Minister Winston Churchill of Britain in Yalta in 1945 to carve up postwar Europe.

Mr. Putin believes that Russia’s vast nuclear arsenal still makes it a world power, even though Russia produces very little that the rest of the world wants apart from energy.

Mr. Putin, having called the 1991 breakup of the Soviet Union “the greatest geopolitical catastrophe of the century,” has sought for decades to reassert Moscow’s control over Ukraine.

Russia and Ukraine have held three rounds of talks in Istanbul, and Moscow has used those meetings to try to achieve territorial gains that proved elusive on the battlefield.

Mr. Putin could well make the same maximalist demands at any meeting with Mr. Trump: claiming eastern Ukraine as Russian; keeping Ukraine out of NATO; preventing the alliance from expanding into former Soviet realms; limiting the size of Ukraine’s military and ensuring that its government is friendly toward Moscow.

What’s at stake for Trump?

One of Mr. Trump’s campaign promises was to end the war in Ukraine in 24 hours after taking office for the second time. More than 200 days have passed, but he still considers himself a supreme deal maker. He has also made no secret of wanting a Nobel Peace Prize, and has linked his deserving of the prize to his efforts in Ukraine, among other conflicts.

“Everyone agrees this War must come to a close, and we will work towards that in the days and weeks to come,” Mr. Trump wrote last week on his social media platform.

His position on the war has been volatile. Earlier this year, he seemed to align himself with the Kremlin, limiting military aid to Ukraine for a time and browbeating Mr. Zelensky during a notorious Oval Office meeting in February.

But as his frustration with Mr. Putin grew, he recently authorized more arms sales intended for Ukraine. He criticized Russia’s bombardment of Ukrainian cities as both “disgraceful” and “disgusting.” And a month ago, he directly criticized Mr. Putin.

Speaking to reporters on Wednesday, Mr. Trump said “there will be very severe consequences” for Russia if Mr. Putin does not agree to halt the war after the Friday meeting. Asked if he believed he could convince Mr. Putin to stop targeting Ukrainian civilians, Mr. Trump said the two leaders had already discussed that.

“I’ve had a lot of good conversations with him, and then I go home and see a rocket hit a nursing home, or a rocket hit an apartment building and people are laying dead in the streets,” Mr. Trump said.

What leverage does the U.S. have over Russia?

Although Mr. Trump has threatened severe direct and secondary sanctions against Russia in order to try to end the war, he has conceded that they might be ineffective.

While previous American presidents might have agreed to a summit as a reward for concessions toward a peace deal, there is no sign that Mr. Putin has changed his attitude toward rejecting any such outcome.

Continued energy sales have allowed Russia to endure the toughest Western sanctions imposed thus far, and the country has minimal direct trade with the United States. Mr. Trump has not imposed the sharp tariffs on Russian imports levied against some American trading partners.

Mr. Trump said in an interview with CNBC last week that “Putin will stop killing people if you get energy down another $10 a barrel.” But Mr. Trump has not moved to sanction China, the largest importer of Russian oil, and Indian officials have said they intend to continue buying Russian oil.

What was Ukraine’s reaction?

Mr. Zelensky has said that any peace deal that excludes Ukraine would be stillborn.

The five points agreed on in the phone call between Mr. Trump and European leaders included keeping Ukraine “at the table” for follow-up meetings on the war and refusing to discuss peace terms, like swaps of land between Russia and Ukraine, before a cease-fire is put in place.

The principles also include security guarantees for Ukraine after the war — including retaining its right to potentially join NATO in the future — and a commitment to ramping up economic pressure on Russia if negotiations fail to reach an agreement. Europe, like Ukraine, will not be represented at the summit.

Despite the enormous toll that the war has taken on Ukraine in death and destruction, polls indicate that a solid majority of Ukrainians reject the idea of making the territorial and other concessions demanded by the Kremlin.

Peter Baker, Katie Rogers, Constant Méheut and Steven Erlanger contributed reporting.