The larger-than-life statue sits atop the US Embassy, near where Reagan gave his "tear down this wall" speech. Merkel thanked the US for its help, but she reserved her praise for a different former US president.
US Secretary of State Mike Pompeo unveiled the 7-foot (2.1-meter) statue, hailing it as a "monumental moment."
The statue sits on the embassy's terrace, overlooking the landmark Brandenburg Gate and the site where Reagan gave his famous 1987 speech urging Soviet leader Mikhail Gorbachev to support peace and "tear down this wall."
Pompeo praised Reagan, saying he "courageously denounced the greatest threat to that freedom, the Soviet empire, the evil empire."
Merkel thanks ... Bush
In a press conference earlier with Pompeo, German Chancellor Angela Merkel thanked the United States for its support in reunification, but she mentioned another US leader in her remarks.
"That the USA, along with George Bush, helped and supported us on the path to German reunification is something that we will never forget," she said at the press conference with Pompeo.
Berlin officials have rejected accusations that Reagan has been given short shrift in memorials in the city — pointing out that a plaque already marks the site where he held his speech and that he was named an honorary citizen in 1992.
"The contributions of US Presidents John F. Kennedy and Ronald Reagan to Berlin as well as to German unity are well known in Berlin," Sabine Bangert, a Berlin lawmaker in charge of memorials, told the Associated Press.
"Kennedy's ... 'Ich bin ein Berliner' speech and Ronald Reagan's memorable Berlin sentence from 1987, 'Mr. Gorbachev, tear down this wall,' as well as Barack Obama's speech at the Brandenburg Gate in 2016, are in all of our memories," she added.
From Jacko to Arnie — controversy has never been far away when statues are made. Following the announcement of the Ronald Reagan statue in Berlin, DW takes a look at some of the replicas that have caused most concern.
Image: picture-alliance/empics/A. Davy
He was back
Champion bodybuilder and ex-California governor Arnold Schwarzenegger has a statue in front of the house where the Austrian actor was born, in the southern Austrian village of Thal. In October 2011, Schwarzenegger returned to his hometown to officially open a museum dedicated to his life, the contents of which includes memorabilia, statues and even dumbbells.
Image: picture-alliance/dpa/K. Mills
Question Marx
The German philosopher Karl Marx once said: "Surround yourself with people who make you happy." But not everyone was pleased when China gifted a statue of the socialist revolutionary in 2018 to his hometown of Trier to celebrate his 200th birthday. A German group representing victims of Communism said at the time: "We say yes to a debate about Marx, but no to his worship."
Image: picture-alliance/AP Photo/M. Probst
Head wrong
A bust of footballer Cristiano Ronaldo was met with mirth at its unveiling in 2017. The Portuguese star's head was designed by artist Emanuel Santos to commemorate an airport being renamed after him in Madeira. However, it looked nothing like the ex-Real Madrid forward which sparked many amusing memes on social media. The bust was replaced by a more representative impression a year later.
Image: picture alliance/abaca
Bad
A statue of Michael Jackson, commissioned by Fulham F.C. owner Mohamed Al Fayed, was unveiled outside the club's stadium to a mixed reaction in 2011. The decision made the club a "laughing stock" according to fans. Al Fayed responded defiantly saying: "If some stupid fans don't understand and appreciate such a gift this guy gave to the world, they can go to hell." In 2013, the statue was removed.