* Exports in Q1 rise 15.1 pct y/y, biggest growth since 2011
* Q1 exports to China, U.S. up 22 pct and 7.6 pct, respectively
* March imports +19.8 pct, well above f'cast
* Demand for iPhone 8, Trump trade policy in focus
* Q1 surplus with U.S. $596 million, was $1.12 bln a year earlier (Recasts and adds analyst comments, details)
By Faith Hung and Emily Chan
TAIPEI, April 10 (Reuters) - Taiwan's first-quarter exports surged the most in six years on solid demand from China and the United States, and the momentum could continue as suppliers stock components for Apple Inc's coming iPhone 8 and other tech gadgets.
Taiwan is one of Asia's major exporters, especially of components of Apple's iPhone and iPad. The island's export trend is a key gauge of global demand for technology gadgets worldwide.
While the latest trade data is solid, uncertainty about the trade policies of U.S. President Donald Trump remains for Taiwan's export-reliant economy.
It's unclear if Trump will impose a border tax on imports, or if the U.S. Treasury might name the island as a currency manipulator in a report due on April 14. (tmsnrt.rs/2p7aUox)
In the first quarter, Taiwan had a trade surplus of $596 million with the United States, compared with $1.121 billion a year earlier, the ministry said.
Taiwan's exports in January-March rose 15.1 percent from a year earlier, the fastest pace for any quarter since January-March 2011, the Finance Ministry said on Monday.
In March alone, exports climbed 13.2 percent, matching the forecast in a Reuters poll and taking a streak of annual increases to six months.
"March exports benefited from continued stable recovery of the global economy, semiconductor demand staying solid and lower-based prices for oil and basic metals," the ministry said.
Exports in the January-March quarter to the two biggest markets, China and the U.S., were up 22 percent and 7.6 percent, respectively. For March alone, the gains were 16.8 percent and 10.6 percent in March.
Imports in March surged 19.8 percent from a year earlier, well above the poll forecast for 12.3 percent. It was the seventh straight gain for a month, and the biggest since April 2011, the ministry said.
"Taiwan has fully caught up with the global economic recovery, so exports should remain solid in H2," said Rick Lo, an economist of Fubon Financial Holding.
"And the upcoming iPhone 8 should help Taiwan run ahead of the competitive pack," he said, adding he expected the central bank to hold its policy rate steady for the second quarter.
Taiwan manufacturing sector's momentum picked up at the end of the first quarter, with output, new orders and employment all rising at faster rates in March than in the previous month, according to survey firm Markit.
The local currency appreciated 6 percent in the first quarter, taking a bite out of exporters' revenue, which will likely prompt the government to revise its 2017 GDP growth forecast slightly downward, some analysts said.
"The government might have to trim down its forecast a little bit," said analyst Lucas Lee of Mega Securities in Taipei. The current forecast stands at 1.92 percent for 2017.
Taiwan Semiconductor Manufacturing Co (TSMC), the world's top contract chip maker, said on Monday the stronger-than-expected Taiwan dollar cut into its January-March revenue by T$6 billion.
This would seem to confirm investor concerns that TSMC's earnings will take a hit from forex losses. TSMC is set to report its first-quarter earnings results Thursday. The company said sales were 17.5 percent higher than a year earlier. (Additional reporting by Jeanny Kao and Loh Liang-sa; Editing by Richard Borsuk)