WASHINGTON — European leaders and US lawmakers warned that President Donald Trump’s threatened tariffs linked to Greenland risk damaging transatlantic relations, as protesters gathered outside the US consulate in Nuuk and European officials prepared emergency talks.

Demonstrators rallied Saturday in front of the US consulate in the Greenlandic capital to protest Trump’s policy toward the autonomous Danish territory, amid rising diplomatic tensions over his comments on acquiring Greenland and using tariffs as leverage.

European diplomats raised immediate questions over how the White House could implement such tariffs, noting that the European Union functions as a single economic zone for trade.

European Union foreign policy chief Kaja Kallas warned that divisions between the United States and Europe would benefit China and Russia.

“If Greenland’s security is at risk, we can address this inside NATO,” Kallas said in a social media post. “Tariffs risk making Europe and the United States poorer and undermine our shared prosperity.”

Trump’s move also drew domestic criticism in the United States. Democratic Sen. Mark Kelly of Arizona said threatened tariffs on US allies would hurt Americans while damaging Washington’s global standing.

“Troops from European countries are arriving in Greenland to defend the territory from us. Let that sink in,” Kelly wrote on social media. “The damage this President is doing to our reputation and our relationships is growing, making us less safe.”

Norway and the United Kingdom, which are not members of the EU, were also drawn into the debate. It remained unclear whether Trump’s proposed tariffs would target the entire 27-member bloc. EU envoys scheduled emergency talks for Sunday evening to consider a coordinated response.

European Council President António Costa and European Commission President Ursula von der Leyen pledged solidarity with Denmark and Greenland, warning that tariffs would “undermine transatlantic relations and risk a dangerous downward spiral.”

“Europe will remain united, coordinated, and committed to upholding its sovereignty,” they said in a joint statement.

Trump’s tariff threat also prompted rare criticism from some of his populist allies in Europe. Italian Prime Minister Giorgia Meloni, considered one of Trump’s closest allies on the continent, said the proposed tariffs were “a mistake,” adding that recent European troop deployments to Greenland were intended to deter unnamed external threats, not the United States.

In France, Jordan Bardella, president of the far-right National Rally party, urged the EU to suspend last year’s tariff agreement with Washington, calling Trump’s stance “commercial blackmail.”

In Britain, criticism spanned the political spectrum. Reform UK leader Nigel Farage said the tariffs would harm the UK, while Prime Minister Keir Starmer described the move as “completely wrong” and said his government would raise the issue directly with Washington.

The foreign ministers of Denmark and Norway are expected to address the crisis later Sunday during a joint news conference in Oslo. — Agencies