Washington (AFP) – US Secretary of State John Kerry warned Tuesday that he “will not go quietly into the night” as President-elect Donald Trump’s incoming administration prepares to shake up US foreign policy.

Addressing an association of women diplomats, Kerry said he would help ensure a smooth handover of power in his department but would continue to argue for environmental protection, foreign aid and strong alliances.

“We’re going to have one hell of a debate over the next few years, I can assure you, and I can promise you this… I am not going to go quietly into the night,” he said, to warm applause.

The 72-year-old Democrat did not mention Trump by name, but his speech was a wide-ranging defense of policies the incoming Republican and his conservative and nationalist supporters have threatened to overturn.

He insisted the Iran deal had made the world safer by blocking Tehran’s path to a nuclear weapon and the Paris climate accord would help stave off “a dire threat to our security and the future prosperity of our planet.”

On the campaign trail, Trump threatened to tear up or renegotiate both these accords and called into question the future of US military alliances, accusing European and Asian partners of not pulling their weight.

“We cannot survive as a fact-free nation,” Kerry declared, urging leaders to heed the warnings of climate science and to invest in green technology rather than a return to coal that Trump advocated on the stump.

“My friends, election outcomes matter, but the democratic process matters much, much more,” Kerry said, acknowledging that fear of a changing world had motivated many voters but decrying the tone of debate.

“After the turmoil of the past few months, it is essential that we restore civility, honesty, and reasonableness — common sense — to the policy debates we have in this country.

“It’s also essential that we not turn our back on the alliances, friendships and principles that have enabled the United States to lead in the world so productively and for so long.”

Trump has yet to decide who will replace Kerry as Washington’s top diplomat when he takes office on January 20 next year.

Former Massachusetts governor Mitt Romney and former general and CIA chief David Petraeus are reported to be the frontrunners for the post.