Republican presidential candidate Ted Cruz is criticizing President Obama for his trip to Cuba, saying Sunday the president’s trip will “legitimize the corrupt and oppressive Castro regime.”

“On Sunday, President Barack Obama, a retinue of celebrities in tow, is expected to arrive in the Cuban capital to hang out with Raúl Castro and his henchmen, all of which will be breathlessly documented by the media mavens along for the ride,” Cruz wrote in the piece published in Politico with the title, “In Cuba, Obama Will Legitimize the Corrupt and Ignore the Oppressed.”

He also tweeted about the president’s trip, pushing out a link to his piece. 

I have a word for the people of Cuba who will witness the gaudy spectacle in Havana: America has not forgotten you: https://t.co/AiTSTraOPA

— Ted Cruz (@tedcruz) March 20, 2016

{mosads}”Meanwhile, political prisoners languishing in dungeons across the island will hear this message: Nobody has your back. You’re alone with your tormentors. The world has forgotten about you.”

Cruz said Castro denies the existence of the political prisoners.

“There will be no mojitos at the U.S. Embassy for them,” he wrote.

There are more than 100 long-term “prisoners of conscious” in Cuba, he wrote, according to news reports. But he noted the Castro regime does not allow international organizations to have access to its prisons, so the number is hard to determine.

“But we know they are there and that hundreds are held for shorter periods, and beaten in prison regularly,” he said.

In his piece, the Texas senator said there were 1,141 Cubans detained for political reasons last month according to the independent Cuban Commission for Human Rights and National Reconciliation.

“So sycophancy is having the effect is always does: It is telling our enemies that they can behave with impunity,” he wrote.

Cruz wrote that his father was Cuban and was “beaten and tortured by Batista’s regime.” But his father and his aunt, who were “brutalized by Castro’s thugs,” found freedom in the United States.

“That freedom can come to Cuba, and I pledge to work to make it so. But it cannot happen by enriching and empowering the dictatorship, while they export terrorism throughout Latin America,” he wrote.

“And it cannot happen by forgetting the heroism and suffering of the brave souls who have opposed the Castros for so many decades.”

Obama landed in Cuba with his family Sunday afternoon. He is the first sitting president to make the trip to the Communist island nation in nearly 90 years. During his trip, he’s expected to meet with Castro and give a speech in Havana.

GOP front-runner Donald Trump also weighed in on the Cuba visit, tweeting Sunday evening about the fact that Castro was not at the airport to meet Obama.