Greenland's politicians have condemned plans for high-profile US visits, in the wake of President Donald Trump's threats to take over the island.

Second Lady Usha Vance will make a cultural visit this week, and a separate trip is expected from Trump's National Security Adviser Mike Waltz.

Outgoing Greenlandic Prime Minister Mute Egede described the plan as aggressive, and said the duo had not been invited for meetings. Meanwhile, the island's likely next leader accused the US of showing a lack of respect.

Greenland - the world's biggest island, situated between the Arctic and Atlantic Oceans - has been controlled by Denmark, nearly 3,000km (1,860 miles) away, for about 300 years.

It governs its own domestic affairs, but decisions on foreign and defence policy are made in Copenhagen. The US has long held a security interest - and has had a military base on the island since World War Two.

It is also thought Trump is interested in the island's rare earth minerals. His son Donald Jr visited Greenland before Trump's inauguration in January.

Announcing Mrs Vance's visit, the White House said the second lady would visit historical sites and attend the Avannaata Qimussersu, Greenland's national dogsled race.

Her delegation - including her son - would be there to "celebrate Greenlandic culture and unity", the statement said.

Waltz's trip was confirmed by a source who spoke to the BBC's US partner, CBS News. He is expected to visit before Mrs Vance and to travel with Energy Secretary Chris Wright, according to the New York Times.

Outgoing PM Egede described Waltz's visit in particular as a provocation. "What is the security advisor doing in Greenland? The only purpose is to show a demonstration of power to us," he told Sermitsiaq newspaper.

Speaking to the same paper, Greenland's probable next PM Jens-Frederik Nielsen accused the American officials of showing the local population a lack of respect.

US National Security Council spokesman Brian Hughes said the United States has a vested interest in the Arctic, and so "it should not be a surprise the National Security Advisor and Secretary of Energy are visiting a US Space Base to get first-hand briefings from our service members on the ground".

He said that the visit is also an opportunity to " build on partnerships that respects Greenland's self-determination and advances economic cooperation" and to "learn about Greenland, its culture, history, and people".

Trump appeared to escalate his campaign to take over the island during a conversation with Nato Secretary-General Mark Rutte earlier this month.

Greenland was already on the defensive about Trump's talk of a takeover, but he sent further shockwaves by implying he might ask to take the island with support of Nato, a military alliance of which Denmark is also a part.

"You know, Mark, we need that for international security... we have a lot of our favourite players cruising around the coast, and we have to be careful," Trump said. "We'll be talking to you."

When asked about the prospect of annexation, Trump said: "I think that will happen."

The move prompted Greenland's leading political parties to issue a joint statement to condemn the American president's "unacceptable behaviour".

The issue took centre-stage in the recent election, during which Egede's governing Inuit Ataqatigiit party was defeated in a surprise result by Nielsen's Democratic party, which favours a gradual approach to independence from Denmark.

Earlier this month, during a speech to the US Congress, Trump said he strongly supported the people of Greenland's right to determine their own future. "If you choose, we welcome you into the United States of America," he said.

According to recent polls, almost 80% of Greenlanders back independence from Denmark. But an opinion survey in January suggested an even greater number rejected the idea of becoming part of the US.