Secretary of State John Kerry became the highest-ranking US government official to visit Antarctica Friday, citing global risks of climate change and the importance of aggressive action to counter it.

An ardent champion in the fight against climate change, Kerry's historic tour -- one of his last trips as the top US diplomat -- came two weeks after the October 28 international agreement that created the world's largest marine protected area.

After arriving at the McMurdo Station, a United States Antarctic research center, Kerry toured the scenic McMurdo Dry Valleys after a scheduled visit to the South Pole was cancelled due to inclement weather.

The chief US diplomat, who will leave his post on January 20 as the Donald Trump administration takes office, declined to comment on Trump's electoral victory.

Kerry did allude to the Republican president-elect's denial of climate science, however, urging citizens to organize and demand bolder action from their elected representatives to limit emissions.

Despite the historic climate rescue pact reached in Paris last year, Kerry told an audience of scientists and staff members working in Antarctica that "we haven't won the battle yet."

"We need to get more of a movement going," Kerry said. "We need to get more people to engage."

Earlier in the week Kerry had congratulated President-elect Donald Trump and said he aimed to hand over power "without missing a beat" on important foreign policy issues.

"I want to offer my congratulations to President-elect Donald Trump and wish him well," he told reporters in the New Zealand city of Christchurch, where he was prior to his journey to Antarctica.

Kerry, who has worked diligently on issues such as climate change for the Obama administration, said the policy challenges that the United States faces have not altered because of the election.

Next week Kerry is scheduled to attend the Morocco global climate conference, a meeting tasked with implementing the landmark Paris climate treaty.

"I'll have a lot more to say about the subject of Antarctica and climate change when I get to Marrakesh," Kerry had told reporters in Christchurch.

The State Department said that Kerry will deliver a speech "that highlights the urgency of addressing climate change and the importance of continued ambitious climate action around the world/"