German Chancellor Angela Merkel says she understands reporters' questions surrounding her health after two incidents this month in which she was seen shaking at public events, but insisted: "I'm fine."

Merkel said Saturday at the end of the Group of 20 summit in Japan that included a long-distance flight and gruelling negotiations with other world leaders that "I'm convinced, just as this reaction occurred it will go away again."

The 64-year-old appeared unsteady and was seen shaking at a ceremony in Berlin on Thursday. She appeared to clutch her arms together to keep herself still as she attended an event with German President Frank-Walter Steinmeier on Thursday.

The incident, at a farewell ceremony for Justice Minister Katarina Barley, was captured on a live feed by the Reuters news agency. At one point she was handed a glass of water, which she waved away.

Merkel's spokesperson later told CNN that the chancellor is "fine."

"Everything is taking place as planned. The chancellor is well," he added.

The chancellor attended the country's parliament half an hour later for the swearing-in of the new justice minister. According to Reuters, she then appeared relaxed and showed no signs of shaking as she talked and laughed with her vice chancellor, Olaf Scholz.

Earlier this month Merkel was seen shaking dramatically as she met Ukrainian President Volodymyr Zelensky in Berlin. She blamed dehydration for that incident.

"Since then I have drunk at least three glasses of water -- I obviously needed that and so I'm doing very well now," Merkel told reporters at a press conference with Zelensky shortly after video of her tremors was circulated.

Tremors can be caused by a number of conditions, ranging from neurological disorders to less serious issues such as medicinal side effects, stress or caffeine consumption.

Germany is in the midst of a record-breaking heatwave, with temperatures hitting 38.6 degrees Celsius in parts.

Merkel, who has been chancellor since 2005, is approaching the end of her lengthy tenure.

She will not seek reelection when her current term ends in 2021, she announced last year, telling reporters the position had been a "very challenging and fulfilling task."

Annegret Kramp-Karrenbauer, widely seen as Merkel's protege, was elected as leader of the Christian Democratic Union party last year and will likely lead it into the 2021 federal elections.