German Chancellor Angela Merkel attends a ceremony where the country's new Justice Minister was given her certificate of appointment by the German President at the presidential Bellevue Palace in Berlin on June 27, 2019. Image Credit: AFP

German Chancellor Angela Merkel on Thursday had a second brief spell of shaking in just over a week, renewing questions over her state of health.

Merkel, aged 64, was seen trembling briefly and clasping her hands during a swearing-in ceremony for the new justice minister alongside President Frank-Walter Steinmeier, according to footage on German TV channel NTV. Moments later she appeared to be doing well when seen in the plenary of the Bundestag, the country's lower house of parliament.

She is due to travel to a G-20 summit of leaders in Osaka, Japan, later on Thursday.

'Everything will take place as planned. The chancellor is doing fine,' her spokesman, Steffen Seibert, told the German news agency DPA.

On June 18 Merkel momentarily shook during a ceremony with Ukrainian President Volodymyr Zelenskiy.

Then, she said it was the result of not drinking enough water.

German news agency DPA said that despite the spell of very hot weather it was cool during the ceremony in Bellevue Castle, where President Frank-Walter Steinmeier was presenting Justice Minister Christine Lambrecht.

Last time, Mrs Merkel trembled while standing next to Ukraine President Volodymyr Zelensky in the hot sunshine. She said she had felt revived after drinking some water.

Last year, Merkel gave up her role as CDU leader and plans to leave politics after her term as chancellor ends with the next national elections, which are slated for 2021 at the latest. She has come under pressure after the ruling parties did poorly in European elections in May and her coalition threatens to fall apart.

Merkel is in her fourteenth year as chancellor.