China is demanding the release of telecoms giant Huawei's chief financial officer, who has been detained in Canada.
Meng Wanzhou, the daughter of the company's founder, could face extradition to the US.
She was arrested in Vancouver on 1 December, but the news was not made public at her request.
The charges remain unknown but the US has been probing Huawei over possible violation of sanctions against Iran.
Canada's ministry of justice confirmed the date and place of Ms Meng's arrest and added: "She is sought for extradition by the United States, and a bail hearing has been set for Friday."
It said it could not say more as Ms Meng had sought a ban on the publication of details and this had been ordered by the courts.
A spokesman for the US justice department in the Eastern District of New York - which Huawei said had brought the charges - declined to comment.
Huawei said it was "not aware of any wrongdoing by Ms Meng".
A Chinese foreign ministry spokesperson told reporters her detention was possibly a rights abuse.
"The detention without giving any reason violates a person's human rights.
"We have made solemn representations to Canada and the US, demanding that both parties immediately clarify the reasons for the detention, and immediately release the detainee to protect the person's legal rights."
Canadian Prime Minister Justin Trudeau said his government had no involvement in the arrest.
Mr Trudeau said Ottawa had been given a few days' advance notice about the plan to arrest Meng Wanzhou. He declined to give further details, given that Ms Meng faces a bail hearing.
The news pummeled stock markets already nervous about increased tension between the United States and China and prompted experts to predict that an angry Beijing would retaliate against Canada.
"The appropriate authorities took the decisions in this case without any political involvement or interference ... we were advised by them with a few days' notice that this was in the works," Mr Trudeau told reporters in Montreal in televised remarks.
Asked whether he had spoken to the Chinese premier or the ambassador, Mr Trudeau said he had had no conversations with international counterparts about the case.
US President Donald Trump's national security adviser, John Bolton, said in an interview with National Public Radio that he knew in advance about the arrest, according to an NPR reporter.
Mr Bolton said he did not know if the US president was aware in advance of the arrest of Ms Meng, the day Mr Trump struck a 90-day truce on trade in a meeting with Chinese President Xi Jinping in Argentina, NPR reporter Steve Inskeep said in a tweet.
"I knew in advance. That is something we get from the Justice Department," the tweet quoted Mr Bolton as saying.
Huawei is one of the largest telecommunications equipment and services providers in the world, recently passing Apple to become the second-biggest smartphone maker after Samsung.
European shares hit a two-year low and indexes across Asia dropped sharply following the arrest.
US media have also reported that Huawei is under investigation for potential violations of US sanctions against Iran.
One report in the New York Times said the US commerce and treasury departments had subpoenaed the firm over suspected violation of sanctions against both Iran and North Korea.
US lawmakers have repeatedly accused the company of being a threat to US national security, arguing that its technology could be used for spying by the Chinese government.
Reacting to the arrest, US Senator Ben Sasse told Associated Press that China was aggressively engaged in undermining US national security interests, often "using private sector entities".
"Americans are grateful that our Canadian partners have arrested the chief financial officer," he said.
In a statement, Huawei said it had complied with "all applicable laws and regulations where it operates, including applicable export control and sanction laws and regulations of the UN, US and EU."
The arrest is a top trending topic on Chinese social media, BBC Monitoring says, with many users criticising the US and Canada for what they call "low" and "bullying" tactics.
Meanwhile, Ms Meng's arrest comes at a sensitive time for US-China relations. The nations are engaged in a trade war that has seen both impose duties of billions of dollars on one another's goods.
But concerns the arrest would impact the 90-day tariff truce negotiated between the two nations at the G20 have not yet materialised. China announced in a regular press briefing yesterday that it would "immediately" implement the measures agreed.
It also coincides with moves to restrict the use of Huawei technology in Western countries. The US, Australia and New Zealand have blocked the use of the Chinese firm's equipment in infrastructure for new faster 5G mobile networks.
Why is Huawei a concern to the West?
Some Western governments fear Beijing will gain access to fifth-generation (5G) mobile and other communications networks through Huawei and expand its spying ability, although the firm insists there is no government control.
Security concerns recently led BT to bar Huawei equipment from the heart of the 5G network it is rolling out in the UK.
New Zealand turned down Huawei equipment from being used in its rollout of 5G network over national security concerns, after Australia imposed a similar ban on both Huawei and fellow communications firm ZTE.
The US has brought a number of legal cases against Chinese technology firms, with accusations such as cyber-security theft and violations of Iran sanctions.
Earlier this year, it barred US companies from exporting to ZTE, effectively shutting down the firm. The US later replaced the ban with a fine and governance changes.
The US has also restricted US firms from selling parts to Chinese chipmaker Fujian Jinhua.
The UK has not blocked firms from using Huawei, although BT, which dominates the UK's telecoms network, said this week it would not use the Chinese firm's equipment in its "core" 5G infrastructure.
- BBC / Reuters