Monday's hastily assembled meeting comes after Trump met on Friday with Russian President Vladimir Putin and has said that the onus is now on Zelenskiy to agree to concessions that he said could end the war.
"If everything works out today, we'll have a trilat," Trump said, referring to possible three-way talks among Zelenskiy, Putin and Trump.
"We're going to work with Russia, we're going to work with Ukraine."
Trump also said he plans to talk to Putin after his meetings with Zelenskiy and European leaders.
Zelenskiy also expressed openness to trilateral talks.
"We are ready for trilateral as president said," Zelenskiy said at the start of his meeting with Trump.
"It's a good signal about trilateral. I think this is very good."
Trump is first holding one-on-one talks with Zelenskiy.
The two are then scheduled to gather with European Commission President Ursula von der Leyen, French President Emmanuel Macron, British Prime Minister Keir Starmer, German Chancellor Friedrich Merz, Italian Premier Giorgia Meloni, Finnish President Alexander Stubb and NATO Secretary-General Mark Rutte.
Trump said that he and Zelenskiy would be discussing potential security guarantees for Ukraine with the European leaders.
"They want to give protection," Trump said of European allies.
"They feel very strongly about it and we'll help them out with it. I think it's very important."
The European leaders were left out of Trump's summit with Russian President Vladimir Putin last Friday, and they want to safeguard Ukraine and the continent from any widening aggression from Moscow.
Many arrived at the White House with the explicit goal of protecting Ukraine's interests — a rare show of diplomatic force.
By coming as a group, they hope to avoid debacles like Zelenskiy's February meeting in the Oval Office, where Trump chastised him for not showing enough gratitude for US military aid.
The meetings are also a test of America's relationship with its closest allies after the European Union and the United Kingdom accepted Trump's tariff hikes partly because they wanted his support on Ukraine.
Ahead of the meeting, Trump suggested that Ukraine could not regain Crimea, which Russia annexed in 2014, setting off an armed conflict that led to its broader 2022 invasion.
Trump's sitdown in Alaska with Putin yielded the possible contours for stopping the war in Ukraine, though it was unclear whether the terms discussed would ultimately be acceptable to Zelenskiy or Putin.
On the table for discussion with European leaders are possible NATO-like security guarantees that Ukraine would need for any peace with Russia to be durable.
Putin opposes Ukraine joining NATO outright, yet Trump's team claims the Russian leader is open to allies agreeing to defend Ukraine if it comes under attack.
"Clearly there are no easy solutions when talking about ending a war and building peace," Meloni told reporters.
"We have to explore all possible solutions to guarantee peace, to guarantee justice, and to guarantee security for our countries."
The European leaders are aiming to keep the focus during the White House talks on finding a sustainable peace and believe forging a temporary ceasefire is not off the table, according to a European official.
