German Chancellor and conservative Christian Democratic Union (CDU) leader Angela Merkel gives a speech during a CDU election campaign rally in Berlin September 21, 2013.

Prime Minister David Cameron of Britain (centre L-R) , President Barack Obama, Chancellor Angela Merkel of Germany, Jose Manuel Barroso, President of the European Commission, and others watch the overtime shootout of the Chelsea vs. Bayern Munich Champions League final in the Laurel Cabin conference room during the G8 Summit at Camp David, Maryland, May 19, 2012. ]

German Chancellor Angela Merkel looks over at U.S. President George W. Bush during a news conference at his ranch in Crawford, Texas, November 10, 2007.

Italian Prime Minister Silvio Berlusconi (C) speaks with France's President Nicolas Sarkozy and German Chancellor Angela Merkel (L) during a news conference following a summit to discuss the international financial crisis at the Elysee Palace October 4, 2008.

German Chancellor Angela Merkel lights a candle at the memorial of the divided city and the victims of communist tyranny during a ceremony marking the 30th anniversary of the fall of the Berlin Wall at the Wall memorial on Bernauer Strasse in Berlin, Germany, November 9, 2019.

German Chancellor Angela Merkel looks at a combat diver during her visit to Naval Base Command in Kiel, Germany, January 19, 2016.

German Chancellor Angela Merkel is reflected in a table as she arrives for a meeting with social workers in Berlin April 30, 2009.

German Chancellor Angela Merkel looks at the painting "Girl Reading a Letter at an Open Window" as she opens the largest exhibition on the Dutch painter Johannes Vermeer in Germany - "Johannes Vermeer. On Reflection" at the Old Masters Picture Gallery of the Staatliche Kunstsammlungen Dresden (SKD), Germany, September 9, 2021.

German Chancellor Angela Merkel of the Christian Democratic Union (CDU) and her husband Joachim Sauer (back) smile as they arrive to cast their votes for the general election in Berlin, September 27, 2009.

Angela Merkel, German Chancellor and leader of the conservative Christian Democratic Union party (CDU) smiles as she addresses a news conference at the CDU party headquarters in Berlin September 28, 2009. Merkel's conservatives vowed on Monday to seal a coalition deal, including tax cuts, with the pro-business Free Democrats (FDP) within a month after winning Germany's election (Bundestagswahl).

German Chancellor Angela Merkel gestures during a election campaign in the western town of Soest April 26, 2010.

(L-R first row) Romania's President Traian Basescu, France's President Nicolas Sarkozy, (L-R second row) Vietnam's Prime Minister Nguyen Tan Dung, German Chancellor Angela Merkel and Polish Prime Minister Donald Tusk, (L-R third row), Japanese Prime Minister Naoto Kan and Finland's Prime Minister Mari Kiviniemi pose for an official photo during the Asia-Europe Meeting (ASEM) in Brussels October 4, 2010.

Pope Francis (R) gestures as he talks to German Chancellor Angela Merkel during a private audience at the Vatican, May 18, 2013.

Germany's Chancellor Angela Merkel and U.S. President Donald Trump hold a joint news conference in the East Room of the White House in Washington, U.S., March 17, 2017.

Angela Merkel, German Chancellor and leader of the conservative Christian Democratic Union party (CDU) reacts after first exit polls in the German general election (Bundestagswahl) at party headquarters in Berlin September 27, 2009.

(L-R) German Chancellor Angela Merkel, Greek Prime Minister Alexis Tsipras, European Central Bank President Mario Draghi, French President Francois Hollande and European Commission President Jean Claude Juncker take part in a euro zone EU leaders emergency summit on the situation in Greece in Brussels, Belgium, July 7, 2015.

German Construction Minister Angela Merkel (L) jokes with Justice Minister Sabine Leutheuser-Schnarrenberger (R) as she notices they are dressed with similar jackets prior to a weekly cabinet meeting, February 22.

German Chancellor Angela Merkel waits for India's Prime Minister Narendra Modi in the Chancellery in Berlin, April 14, 2015.

Russian President Vladimir Putin talks with German Chancellor Angela Merkel as they attend the International 70th D-Day Commemoration Ceremony in Ouistreham June 6, 2014.

German Chancellor Angela Merkel and Britain's Queen Elizabeth smile as a robot waves during their visit at the Technical University of Berlin (TU Berlin) in Berlin, Germany June 24, 2015. Queen Elizabeth and the Duke of Edinburgh are on a three day state visit to Germany.

A migrant takes a selfie with German Chancellor Angela Merkel outside a refugee camp near the Federal Office for Migration and Refugees after registration at Berlin's Spandau district, Germany September 10, 2015.

Russian President Vladimir Putin (R) meets with German Chancellor Angela Merkel at the Kremlin in Moscow, Russia, May 10, 2015.

Greece's Prime Minister Alexis Tsipras (R) chats with Germany's Chancellor Angela Merkel prior to a meeting over the Balkan refugee crisis with leaders from central and eastern Europe at the EU Commission headquarters in Brussels, Belgium, October 25, 2015.

German Chancellor Angela Merkel wears Google Glass eyewear as she visits a booth of Nokia where students developed an interactive communication software to repair mobile communications equipment abroad during a Girls Day career event at the Chancellery in Berlin April 27, 2016.

German Chancellor Angela Merkel speaks during a session at the lower house of parliament Bundestag in Berlin, Germany, October 17, 2018.

Christine Lagarde, Managing Director of the International Monetary Fund (IMF), and German Chancellor Angela Merkel attends a news conference following a meeting of the heads of international economy and finance organizations at the Chancellery in Berlin, Germany, April 5, 2016.

Spain's Prime Minister Jose Luis Rodriguez Zapatero (L) and German Chancellor Angela Merkel wear 3D glasses during the opening ceremony of the CeBIT computer fair in Hanover March 1, 2010.

Britain's Prime Minister Boris Johnson gestures next to German Chancellor Angela Merkel during the G7 summit in Carbis Bay, Cornwall, Britain, June 11, 2021.

U.S. President Barack Obama is welcomed by German Chancellor Angela Merkel upon his arrival at the chancellery in Berlin, Germany, November 17, 2016.

German former Chancellor Gerhard Schroeder (R) leaves after presenting flowers to Christian Democrat (CDU) leader Chancellor Angela Merkel in Berlin November 22, 2005.

German Chancellor and leader of the conservative Christian Democratic Union party CDU Angela Merkel reacts after her speech at the CDU party convention in Essen, Germany, December 6, 2016.

German Chancellor Angela Merkel and leader of the Christian Democratic Union party CDU stands in front of her election campaign tour bus before a CDU board meeting in Berlin September 16, 2013.

Angela Merkel, German Chancellor and leader of the conservative party Christian Democratic Union (CDU) reacts reacts after her re-election as party leader during the party convention of the CDU in Karlsruhe, November 15, 2010.

Germany's Chancellor Angela Merkel arrives at the European Union (EU) council headquarters for an EU leaders summit discussing the EU's long-term budget in Brussels November 23, 2012.

Germany's Chancellor Angela Merkel gestures as she arrives for a two-day European leaders summit in Brussels June 18, 2009.

German Health Minister Horst Seehofer (R) gestures as he talks to Environment Minister Angela Merkel prior to a cabinet meeting in Bonn, July 18. The cabinet is expected to discuss the governments pension report 1998.

German Chancellor Angela Merkel and Russian President Vladimir Putin pose for a picture as he arrives to attend the Libya summit in Berlin, Germany, January 19, 2020. Image for illustrative purposes.

German Chancellor Angela Merkel speaks with U.S. President Barack Obama outside the Elmau castle in Kruen near Garmisch-Partenkirchen, Germany, June 8, 2015.

German Chancellor Angela Merkel rests her head in her hands, as she follows a debate with Labour Minister Franz Muentefering (L) at the German lower house of parliament Bundestag in Berlin June 14, 2007.

German Chancellor Angela Merkel acknowledges the applause as she receives an honorary Doctor of Laws degree during the 368th Commencement Exercises at Harvard University in Cambridge, Massachusetts, U.S., May 30, 2019.

France's President Nicolas Sarkozy (L) gestures beside German Chancellor Angela Merkel at the start of a European Union leaders summit in Brussels March 25, 2010.

French President Emmanuel Macron welcomes German Chancellor Angela Merkel for a working dinner at the Elysee Palace in Paris, France, September 16, 2021.

German Chancellor Angela Merkel, a top candidate of the Christian Democratic Union Party (CDU) for the upcoming general elections reacts at the final election rally in Munich, Germany September 22, 2017.