While America's allies in Europe were mourning the victims of Tuesday's deadly terrorist attacks in Brussels and bracing for a possible follow-up attacks, U.S. President Barack Obama was busy doing the tango and taking in other pleasures on his visits to Cuba and Argentina, observers noted.

Obama seemed unperturbed despite indignant calls from Republican leaders, including presidential candidates Donald Trump and Ted Cruz, for him to cut short his foreign trip and return home in the wake of the Brussels attack that killed at least 34 people and wounded 230 others, including at least nine Americans.

Worse, Obama even had the gall to pose in front of a mural of communist icon Che Guevara in Cuba together with Cuban dictator Raul Castro, prompting former House Speaker Newt Gingrich to call him as the "the first anti-American president," Newsmax reported.

Speaking on Wednesday on Fox News Channel's "Hannity," Gingrich asked Obama: "How can you stand in front of a mural of Che Guevara, who was a murdering thug, who was viciously anti-American? How can you be seen at a ballgame with a dictator who, by the way, was arresting people while Obama was arriving?"

After his Cuba visit, the first by an American president since 1928, Obama flew to Argentina on the second leg of his Latin American mission. There he again drew ridicule when he and first lady Michelle Obama were coaxed onto the dance floor by professional tango dancers at a state dinner hosted by Argentine President Mauricio Macri, according to Newsmax.

Speaking for the Republicans, GOP strategist Anna Navarro commented: "The entire thing is horrible. It reminded me of when he went golfing after James Foley's head was cut off."

In September 2014, Obama played golf on Martha's Vineyard after making a quick statement condemning the beheading of Foley, a freelance journalist from New Hampshire, by Islamic State terrorists. He later admitted that the move was a mistake after widespread outrage by critics.

"It's inexcusable that when the entire world is standing in solidarity with Brussels, is in shock, in grief, the president of the United States is in Cuba sitting next to a dictator who has been in power for 56 years who has ordered the shoot-down of American citizens, who has been anti-American for 56 years," Navarro told John Berman on CNN.

"Eating peanuts and going to the baseball game like he was at Walt Disney World. It's not Walt Disney — and it's a day of grief for the entire world, said Navarro, a former Jeb Bush supporter.

Former presidential adviser David Gergen also castigated Obama for his action. "I would tell the president that when you gave your speech in Cuba, the 38-minute speech and you only gave a few seconds to Brussels, you brushed it off," he said.

"When you go to a baseball game it looks frivolous. Dancing like that. He should have made the hard call and come back and gathered people or look for leadership here," Gergen said. "Restraint does not equal leadership when you are under attack."

Gingrich noted that the dictatorship in Cuba has done nothing to accommodate the United States, just as the North Koreans and Iranians do nothing.

"All of them treat Obama with contempt and because he earns it," he said. "He behaves in ways that are weak, and he allows them to take advantage of him, and I think that's a fact."

Gingrich also criticised Democratic presidential front-runner Hillary Clinton.

"Hillary Clinton, who last night after the Brussels bombing said, we shouldn't really be afraid," he said. "I mean, is she just out of touch? I know she's had Secret Service since 1992, but the fact is the rest of us don't have Secret Service, and we have every reason to be afraid."