By Andrea Shalal, Joe Cash and Benoit Van Overstraeten

WASHINGTON/BEIJING/BRUSSELS (Reuters) - President Donald Trump's move to slap a 10% tariff on most goods imported to the United States, as well as much higher levies on dozens of rivals and allies alike, has intensified a global trade war that threatens to stoke inflation and stall growth.

The sweeping penalties announced against the serene backdrop of the White House Rose Garden on Wednesday immediately unleashed turbulence across world markets and drew condemnation from other leaders now facing the end of decades of trade liberalization that have shaped the global order.

As Asia digested the news on Thursday, Japan's Nikkei share index slumped to an eight-month low, with U.S. and European stock futures also diving as investors scrambled to the safety of bonds and gold.

China, the world's No. 2 economy, faced with a fresh 34% tariff on top of the 20% Trump previously imposed, vowed countermeasures, seemingly taking little heed of a warning by U.S. Treasury Chief Scott Bessent that such moves would lead to escalation.

Close allies like Japan and the European Union were not spared, facing 24% and 20% tariff rates respectively. The base 10% tariffs go into effect on April 5 and the higher reciprocal rates on April 9.

EU chief Ursula von der Leyen described the tariffs as a major blow to the world economy and said the 27-member bloc was prepared to respond with countermeasures if talks with Washington failed.

"The consequences will be dire for millions of people around the globe," she said in a statement.

The "reciprocal" tariffs, Trump said, were a response to duties and other non-tariff barriers put on U.S. goods. He argued that the new levies will boost manufacturing jobs at home.

"For decades, our country has been looted, pillaged, raped and plundered by nations near and far, both friend and foe alike," Trump said.

Outside economists have warned that tariffs could slow the global economy, raise the risk of recession, and increase living costs for the average American family by thousands of dollars.

Canada and Mexico, the two largest U.S. trading partners, already face 25% tariffs on many goods and will not face additional levies from Wednesday's announcement.

Even some fellow Republicans have expressed concern about Trump's aggressive trade policy.

Within hours of Wednesday's announcement, the Senate voted 51-48 to approve legislation that would terminate Trump's Canadian tariffs, with a handful of Republicans breaking with the president. Passage in the Republican-controlled U.S. House of Representatives, however, was seen as unlikely.

Trump's top economist, Stephen Miran, told Fox Business on Wednesday the tariffs would work out well for the U.S. in the long run, even if they cause some initial disruption.

"Are there going to be short-term bumps as a result? Absolutely," Miran, the chairman of Trump's Council of Economic Advisors, told the network's "Kudlow" program.

ENDING 'DE MINIMIS'

The reciprocal tariffs do not apply to certain goods, including copper, pharmaceuticals, semiconductors, lumber, gold, energy and "certain minerals that are not available in the United States," according to a White House fact sheet.

Following his remarks, Trump also signed an order to close a trade loophole used to ship low-value packages - those valued at $800 or less - duty-free from China, known as "de minimis." The order covers goods from China and Hong Kong and will take effect on May 2, according to the White House, which said the move was intended to curb the flow of fentanyl into the U.S.

Chinese chemical makers are the top suppliers of raw materials purchased by Mexico's cartels to produce the deadly drug, U.S. anti-narcotics officials say. A Reuters investigation last year showed how traffickers often route these chemicals through the United States by exploiting the de minimis rule. China has repeatedly denied culpability.

Trump is also planning other tariffs targeting semiconductors, pharmaceuticals, and potentially critical minerals, the official said.

Earlier in the day, the administration said a separate set of tariffs on auto imports that Trump announced last week will take effect starting on Thursday.

Trump previously imposed 25% duties on steel and aluminum and extended them to nearly $150 billion worth of downstream products.

Tariff concerns have already slowed manufacturing activity across the globe, while also spurring sales of autos and other imported products as consumers rush to make purchases before prices rise.

U.S. Representative Gregory Meeks, the top Democrat on the House Foreign Affairs Committee, said he would introduce legislation to end the tariffs. Such a bill has little chance of passing the Republican-controlled Congress, however.

"Trump just hit Americans with the largest regressive tax hike in modern history - massive tariffs on all imports. His reckless policies are not only crashing markets, they will disproportionately hurt working families," Meeks said.

(Additional reporting by Kanishka Singh and Steve Holland in Washington, Joe Cash in Beijing and Benoit Van Overstraeten and Philip Blenkinsop in Brussels; Writing by Andy Sullivan, Joseph Ax and John Geddie; Editing by Alistair Bell, Diane Craft and Lincoln Feast.)