Foreign policy has emerged as the main ideological fissure within the Republican Party as the 2024 nominating contest heats up.
While former President Donald Trump and Florida Governor Ron DeSantis have called for dedicating resources to domestic issues rather than Ukraine, several other declared and likely presidential candidates have portrayed themselves as unwavering defenders of the eastern European county.
Both Pence and Sununu have defended Ukraine before, but their Saturday comments were particularly pointed and come as the Republican foreign policy feud intensifies.
This week, DeSantis said in a statement provided to conservative radio host Tucker Carlson that the Ukraine War was a "territorial dispute," which was not a vital national interest to the U.S.
DeSantis has not declared a presidential run but he is widely expected to do so, and he is by far Trump's most formidable Republican opponent.
Speaking in Iowa, Pence, who is also expected to run, took a jab at the Florida governor.
"I must tell you the war in Ukraine is not a territorial dispute. It is a Russian invasion," he told a group of Republicans near Des Moines.
"I truly do believe that this is a moment of testing for the free world to ensure peace in eastern Europe."
Pence did not criticize Trump, even as the former president opposes dedicating more resources to Ukraine and once called Russian President Vladimir Putin a "genius" for invading the neighboring country.
In a Washington Post opinion column, Sununu, the New Hampshire governor, went after Trump and DeSantis directly.
"Some in the Republican Party have lost their moral compass on foreign policy, as evidenced by former president Donald Trump, who once called Putin's invasion 'genius' and 'savvy,'" Sununu wrote.
Pence is running well behind Trump and DeSantis, vying for a distant third with former United Nations Ambassador Nikki Haley, another Ukraine supporter.
Sununu, a relative moderate who is also considering a run, is polling in the low single digits.
(Reporting by Gram Slattery; Editing by Josie Kao)
By Gram Slattery