Angela Merkel has sought to assuage concerns about her health after a spate of shaking bouts at public events, saying she is feeling fine and looking forward to a healthy life when she steps down in two years.

“I understand questions about my health, and I have already given an answer to this,” said the German chancellor, who recently turned 65. “It is important that I commit myself to the responsibility of acting as head of government. I just would say you have known me for some time and I can perform this role.”

Merkel’s ability to continue in the job she has held for 14 years has been questioned after three public incidents within three weeks in which her entire body appeared to shake.

Angela Merkel says she is in good health after third shaking bout Read more

Speaking at the annual press conference she holds every year before her holiday, she repeated her pledge to step down in 2021, having already resigned as leader of the Christian Democratic party at the end of last year.

In a speech contemplating her life after more than 30 years in politics, which drew laughter from assembled journalists, she said: “I will finish my political work in 2021, but I hope that life will continue after that, and I would like it to continue in a healthy way.”

Pressed once again on how she was feeling, she said: “So many good questions are making me feel just fine.”

She condemned the US president, Donald Trump, for his racist attack on four congresswomen of colour whom he told to “go back” to the “places from which they came”.

“I firmly distance myself from [Trump’s comments] and feel solidarity towards the attacked women.” The German chancellor added: “The strength of America lies in the idea that people of different origins contribute to what makes the country great.”

In the wide-ranging question and answer session, which lasted for 90 minutes, Merkel was relaxed and quick-witted, defending her decision to promote her would-be successor Annegret Kramp-Karrenbauer to the role of defence minister. She said Germany should be proud that a German woman, Ursula von der Leyen – another close Merkel ally – was at the helm of the EU as its president.

She credited environmental activists from the Fridays for Future movement – most notably the 16-year-old Swedish schoolgirl Greta Thunberg, who addressed a rally in Berlin on Friday – with “driving an acceleration” of the government’s actions on climate change, saying the protests meant climate was being dealt with “more decisively” amid “extraordinary weather conditions”, which showed, she said, “what damage is done by not acting on climate policy”.

Merkel has previously praised participants of the Fridays for Future demonstrations, refusing to join other politicians in Germany who have condemned participants for missing school.

Asked whether she believed Britain might hold a second Brexit referendum, Merkel refused to be drawn, saying: “I have no wish to participate in any sort of prognoses.” She said the EU had already negotiated the exit agreement, adding that any movement on the Irish backstop would only be possible if an alternative solution for dealing with the border emerged.

“If we find a solution for management of the border … then the backstop is obsolete [and] no longer relevant,” she said, adding that the future relationship between the EU and the UK was dependent on a solution.

Merkel said she saw “room for manoeuvre” over the conditions of future relations between the UK and the EU, hinting that new talks on a non-binding additional agreement could sketch out the terms of those relations.

She thanked the outgoing British prime minister, Theresa May, for her “reliable and comradely” cooperation during what she said had been a difficult time for May. Merkel said the quality of her cooperation with a new leader would depend on how he acted. When a journalist referred to the new prime minister as Boris Johnson, Merkel swiftly interjected to say that the decision as to who it would be had yet to be made.

Asked what she felt were the qualities needed to be chancellor, Merkel listed “realistic optimism”, “feeling joy” at the task, and a “tireless curiosity in people”.