* Steel inventory at Chinese traders down for third week
* Expectations of seasonal demand pickup
* China blames U.S for trade frictions; Trump voices optimism
By Manolo Serapio Jr
MANILA, April 10 (Reuters) - Chinese iron ore futures jumped more than 2 percent on Tuesday, rebounding after a three-day retreat as steel prices rose, spurred by expectations of a pickup in seasonal demand and a sustained drop in steel stockpiles.
However, worries over trade frictions between the United States and China capped gains in both commodities.
China has stepped up its attacks on the Trump administration over billions of dollars worth of threatened tariffs, but U.S. President Donald Trump again voiced optimism the two sides would hammer out a trade deal.
The most-traded iron ore for September delivery on the Dalian Commodity Exchange was up 2.4 percent at 449.50 yuan ($71) a tonne by 0223 GMT.
“The physical market is still quite stable. We are expecting seasonal demand to increase consumption which will support raw material prices,” said an iron ore trader in Shanghai.
Activity in the construction sector, a big steel user, typically increases as weather warms after winter.
“It’s still quite cold in some parts of China, so I believe it will take one or two weeks before we see construction work fully start,” the trader said.
Iron ore shipments to China from the Port Hedland terminal in top supplier Australia climbed nearly 12 percent in March from a month earlier to 35 million tonnes.
Iron ore for delivery to China’s Qingdao port .IO62-CNO=MB rose 0.6 percent to $63.95 a tonne on Monday, according to Metal Bulletin.
The most-active rebar on the Shanghai Futures Exchange rose 1.3 percent to 3,407 yuan per tonne, gaining for a second session running.
In a sign of demand picking up, inventory of construction steel product rebar at Chinese traders dropped for a third consecutive week, standing at 8.73 million tonnes on April 4, data compiled by SteelHome consultancy showed. SH-TOT-RBARIN
That compared to a nearly five-year peak of 9.78 million tonnes in mid-March.
“Inventory at traders dropped at a faster pace because of stronger demand,” Morgan Stanley said in a report, pointing to a 6.5 percent weekly drop in traders’ inventory for major steel products during the same period.
$1 = 6.2994 Chinese yuan Reporting by Manolo Serapio Jr.; editing by Richard Pullin