Gene Simmons, outspoken founding member of the rock band Kiss, waded into two hot-button political issues on Thursday, siding with President Donald Trump on moving the U.S. embassy in Israel to Jerusalem and building a southern border wall between the U.S. and Mexico.

Simmons, born in the city of Haifa, spoke first about the embassy, pointing to the 1995 Jerusalem Embassy Act, which recognized Jerusalem as the capital of Israel and called for the relocation of the U.S. embassy from Tel Aviv by 1999.

"This president, President Trump, who I've known a little bit here and there, is not the one who passed the legislation," Simmons told CNBC's "Squawk Box" in an interview. "So the president was following what already was agreed on."

However, past presidents in both parties from Bill Clinton to George W. Bush to Barack Obama used the bill's waiver authority to suspend the move, citing concerns about complicating attempts at getting Israelis and Palestinians to reach a peace accord. Both sides claim Jerusalem as their capital.

On Monday, Trump's son-in-law and senior advisor, Jared Kushner, who is Jewish, presided over the opening of the U.S. embassy in Jerusalem, which came about five months after the president formally recognized Jerusalem as Israel's capital and promised the move.

"At the end of the day, this will infuriate some segments of society there," Simmons said, referring to the protests that turned deadly along the Israeli-Gaza border. "Both sides need to stop the hatred," he urged.

Simmons segued from comments on the turmoil in the Mideast to Trump's call for a southern border wall between the U.S. and Mexico and Pope Francis' criticism of the idea.

"The pope is a wonderful human being. I'm a big fan of his. But he came out against a hypothetical wall between American and its neighbor. [He] said that was a bad idea," Simmons said, claiming the pontiff was being hypocritical. "The Vatican has a big wall around it for the same reason. They want to find out who's coming in there. You just can't walk in there."

The pope last year reiterated his criticism of Trump's idea of a border wall.

During the 2016 campaign, the pope said, "A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian."

After meeting the pope just months after his inauguration, Trump exchanged gifts and shook hands.