Former Vice President Mike Pence made an unannounced visit to Ukraine on Thursday, a detour from the presidential campaign trail that was intended to highlight his unwavering support for the nation as it battles Russia and to contrast it with the views of two key Republican rivals: Donald J. Trump and Ron DeSantis.
Both Mr. Trump, the former president, and Mr. DeSantis, the Florida governor, have criticized U.S. involvement in the defense of Ukraine. The United States has provided more than $40 billion in military and humanitarian aid.
During his 12-hour stay, with an NBC News crew accompanying him, Mr. Pence met with Ukraine’s president, Volodymyr Zelensky, and toured a mass burial site, placing flowers at a memorial, according to an adviser.
For more than 16 months, Ukraine has been fighting to repel the Russian invasion, in a war that has claimed the lives of hundreds of thousands of civilians and soldiers.
“Look, the war here in Ukraine is not our war, but freedom is our fight,” Mr. Pence told NBC News. He is the first Republican candidate to visit Ukraine during the 2024 campaign. President Biden was in Kyiv in February.
In his nightly address to his nation, Mr. Zelensky thanked Mr. Pence for his support and said that American support for Ukraine was vital.
Mr. Pence added to NBC News, “I think we’re advancing not only the interests of freedom, but let me be clear, my other message is we’re advancing our national interest.”
The show of solidarity by Mr. Pence, who was Mr. Trump’s vice president, contrasted sharply with the G.O.P.’s top tier of presidential candidates.
During a CNN town hall in May, Mr. Trump, the Republican front-runner, refused to say whether he wanted Ukraine to win the war.
He also would not call President Vladimir V. Putin of Russia a war criminal, saying that doing so would make it more difficult to end the hostilities. Mr. Trump did say Mr. Putin had “made a bad mistake” by invading Ukraine.
Mr. DeSantis, a former House member, has aligned himself more closely with Mr. Trump on U.S. aid for Ukraine.
In a statement to Fox News in March before formally entering the race, Mr. DeSantis said that protecting Ukraine’s borders was not a vital U.S. interest and that policymakers should instead focus attention at home. He was responding to a questionnaire from Tucker Carlson, the conservative commentator who was later fired by the network.
At that time, Mr. DeSantis was criticized by some hawks in the G.O.P. for describing Russia’s invasion of Ukraine as a “territorial dispute.” In an attempt to clarify his remarks, he later called Mr. Putin a “war criminal” who should be “held accountable.”
Jonathan Swan, Maggie Haberman and James C. McKinley Jr. contributed reporting.