On Wednesday, the Virginia State Board of Elections approved the move, which requires voters to sign an oath before they can participate in the March 1 primary. Virginia Democrats did not seek approval of a similar pledge.
In a series of tweets posted Sunday morning, Trump warned that GOP officials were making a "suicidal mistake" by potentially excluding independent voters in a state that has turned purple in recent elections.
The decision could have negative consequences for a candidate like Trump, who has attracted support among independents and conservatives furious with Republican leaders in Washington.
The real estate mogul, who continues to lead in the polls, has openly flirted with the prospect of running as an independent. He recently touted a USA Today poll that showed a majority of his supporters would vote for him if he bolted the GOP and ran as an independent.
Earlier this month, however, at a Republican presidential debate, he flatly ruled out the move.
Also on HuffPost: