Republican front-runner Donald Trump is planning what he calls a "big speech" Monday instead of debating his remaining two opponents for the party's presidential nomination.
Trump was due to take part in the Fox News debate in Salt Lake City, Utah with Texas Senator Ted Cruz and Ohio Governor John Kasich, but said Wednesday Republicans have had "enough debates" and he would not attend.
Kasich said without Trump, he will not go either. Suddenly lacking candidates, Fox News canceled the debate.
FILE - Republican presidential candidate Ohio Gov. John Kasich pumps his fist and celebrates before speaking at his presidential primary election rally in Berea, Ohio, March 15, 2016.
Cruz, who trails Trump 673-410 in the Republican delegate count, hit out at the businessman, branding Trump as "Ducking Donald" and pointing his supporters to the website DuckingDonald.com.
"Donald is scared to debate because he knows Ted Cruz will expose him as unprepared to be president and commander in chief," the site says, urging people to sign a petition for Trump to debate.
The site was registered on January 27, the day after Trump announced he was skipping the Republican debate before the Iowa caucus. Cruz finished first in Iowa, 3 percent ahead of Trump.
Monday's debate was scheduled a day before primaries in Utah and Arizona with a combined 98 delegates at stake. After a flurry of state contests in the past few weeks, the primary calendar is hitting a slow period, particularly for Republicans, who have just Utah, Arizona and a primary in Wisconsin between now and April 19.
How likely is a contested convention?
The Democratic race between former Secretary of State Hillary Clinton and Vermont Senator Bernie Sanders will be a little busier. They compete in the same states as the Republicans, but also have a caucus Tuesday in Idaho, March 26 caucuses in Alaska, Hawaii and Washington, and another in Wyoming on April 9.