By Caroline Valetkevitch and Naomi Rovnick

NEW YORK/LONDON (Reuters) -Major stock indexes and the dollar fell on Friday after U.S. President Donald Trump unleashed his latest trade threats, recommending 50% tariffs on European Union imports from June 1 and saying he may impose a 25% tariff on any Apple iPhones manufactured outside the U.S.

Shares of Apple were down 2.5% in early New York trading, while the Nasdaq was down more than 1%. European shares also fell sharply.

The dollar index, which measures the greenback against a basket of currencies, fell 0.46% to 99.45, with the euro up 0.35% and the dollar down 0.81% against the yen. The dollar index was on track for a weekly loss.

Government bonds in the United States and Europe climbed, however, as the assets suddenly found favor from haven buyers after sustaining heavy pressure this week from rising concerns about Trump's tax cuts and the White House's ballooning debt pile.

Trump said in a post on his Truth Social network: "The European Union, which was formed for the primary purpose of taking advantage of the United States on TRADE, has been very difficult to deal with."

This was the latest event in a jittery week for global markets after Moody's late last Friday downgraded the U.S. credit rating and the U.S. House of Representatives on Thursday narrowly approved Trump's sweeping tax cuts.

"Tariffs are back at the forefront," said Oliver Pursche, senior vice president and advisor for Wealthspire Advisors in Westport, Connecticut.

"I think the 25% tariffs on iPhones and Apple was a little bit of a surprise. It seemed like there was going to be an exemption there, and the market is reacting more to that than the EU news, and is interpreting that as a hardening of the stance by President Trump and the administration as opposed to seeking a negotiating path."

The Dow Jones Industrial Average fell 284.70 points, or 0.68%, to 41,576.68, the S&P 500 fell 51.16 points, or 0.88%, to 5,790.85 and the Nasdaq Composite fell 221.02 points, or 1.17%, to 18,704.71.

MSCI's gauge of stocks across the globe fell 4.88 points, or 0.56%, to 866.13. The pan-European STOXX 600 index fell 1.06%.

The new tax-cut bill is expected to add almost $4 trillion to the U.S. federal government's $36 trillion debt pile.

Yields on 30-year Treasuries, which had hit 19-month highs early on Thursday, were down on Friday in response to fresh tariff fears.

The 30-year bond yield was last down 1.7 basis points at 5.0468%. The yield on benchmark U.S. 10-year notes fell 3.4 basis points to 4.519%, from 4.553% late on Thursday.

Gold, which has surged in recent months as economic anxiety as risen, was higher. Spot gold rose 1.47% to $3,342.49 an ounce.

U.S. crude rose 0.33% to $61.40 a barrel and Brent rose to $64.58 per barrel, up 0.22% on the day.

(Reporting by Caroline Valetkevitch in New York and Naomi Rovnick in London; Additonal reporting by Stella Qiu in Sydney; Editing by Amanda Cooper and Alex Richardson)