* H1 imports from United States up 35 pct y/y - Thai data
* U.S. figures for first five months show little change
* U.S. is Thailand's No. 2 export market this year after China
BANGKOK, Aug 7 (Reuters) - Thai officials voiced hope ahead of a visit by U.S. Secretary of State Rex Tillerson of escaping U.S. pressure over the size of their trade surplus with the United States as their figures point to a jump in imports, but U.S. data shows little change.
A spokeswoman for the State Department's East Asia Bureau said Tillerson, who will be the most senior U.S. official to visit Thailand since a 2014 coup, will discuss a broad range of issues including security, trade and investment.
Tillerson visits Bangkok on Tuesday after attending regional meetings in Manila at the weekend.
A narrowing trade gap would also reduce the risk of Thailand being labelled by Washington as a currency manipulator - the last thing Thailand wants as it struggles with a baht currency that exporters find uncomfortably strong.
According to Thai customs-cleared figures, imports rose 35 percent from a year earlier in the first six months of 2017 while exports to the United States rose 7 percent.
That meant Thailand's trade surplus over the six months narrowed from $6 billion to $4.8 billion.
"We hope higher imports from the U.S. will help ease pressure on this issue... and the trend should continue," Pimchanok Vonkhorporn, head of the commerce ministry's trade policy and strategy office, told Reuters on Monday.
However, U.S. figures calculated using a different methodology showed little change in the gap during the first five months year on year. The U.S. estimate of a Thai trade surplus of $18.9 billion put it in 11th place on U.S. President Donald Trump's list of countries to be investigated.
The growth in Thailand's imports from the United States this year was led by planes and parts, circuit boards, chemicals, metal and machinery and parts, the Thai data showed.
It shows "we haven't conducted any trade protectionist policy", said Thanavath Phonvichai, professor at the University of the Thai Chamber of Commerce.
After being put on the U.S. list, Thailand defended itself with a 22-page justification that covered everything from its support for the United States in the Korean War to investment by U.S. companies in Thailand.
About 40 percent of Thai exports to the United States come from U.S. firms, officials say. Thailand is the world's No. 2 maker of hard drives, with U.S. firm Seagate Technology and Western Digital among big players.
Although the Trump administration has indicated no specific action against Thailand, Trump has ordered a study into the causes of U.S. trade deficits. (Additional reporting by Kitiphong Thaichareon in BANGKOK; and David Brunnstrom in WASHINGTON; Editing by Matthew Tostevin, Amy Sawitta Lefevre and Nick Macfie)