highlights military option@
* Trump says prefers to avoid military action against North Korea
* USS Ronald Reagan heads out on scheduled patrols from Japan
SEOUL/WASHINGTON, Sept 8 (Reuters) - Most South Koreans doubt that North Korea will start a war, a survey showed on Friday, just days after the North's largest nuclear test, as President Donald Trump again highlighted the possibility of a U.S. military response.
Tension on the Korean peninsula has escalated as North Korea's young leader, Kim Jong Un, has stepped up the development of weapons in defiance of U.N. sanctions, testing a string of missiles this year, including one flying over Japan, and conducting its sixth nuclear test on Sunday.
Experts believe the isolated regime is close to its goal of developing a powerful nuclear weapon capable of reaching the United States, something Trump has vowed to prevent.
Still, a Gallup Korea survey showed South Koreans were considerably less concerned about war compared with June 2007, nine months after North Korea conducted its first nuclear test, in September 2006.
The survey found that 58 percent of those questioned felt there was no possibility North Korea would cause a war, while only 37 percent thought it could.
In 2007, 51 percent of respondents said they expected a war, while 45 percent did not.
Trump has repeatedly said all options are on the table in dealing with North Korea and on Thursday said he would prefer not to use military action, but if he did, it would be a "very sad day" for North Korea.
"Military action would certainly be an option. Is it inevitable? Nothing is inevitable," Trump told reporters. "If we do use it on North Korea, it will be a very sad day for North Korea."
Even as Trump has insisted that now is not the time to talk, senior members of his administration have made clear that the door to a diplomatic solution is open, especially given the U.S. assessment that any pre-emptive strike would unleash massive North Korean retaliation.
North Korea says it needs its weapons to protect itself from U.S. aggression and regularly threatens to destroy the United States.
South Korea and the United States are technically still at war with North Korea after the 1950-53 Korean conflict ended with a truce, not a peace treaty.
US CARRIER ON THE MOVE
The USS Ronald Reagan, a nuclear-powered carrier, left its home port in Japan for a routine autumn patrol of the Western Pacific, a Navy spokeswoman said. That area included waters between Japan and the Korean peninsula, she added, without giving any further details.
The Ronald Reagan was out on routine patrol from May until August, and was sent to the Sea of Japan with the another carrier, the USS Carl Vinson, to take part in drills with Japan's Self Defence Forces as well as the South Korean military.
North Korea vehemently objects to military exercises on or near the peninsula, and China and Russia have suggested the United States and South Korea halt their exercises to lower tension.
While Trump talked tough on North Korea, China agreed on Thursday that the United Nations should take more action against it, but it also pushed for dialogue.
The U.N. Security Council is expected to vote on a new set of sanctions soon. North Korea offered fresh vitriol against the pending sanctions, specifically targeting U.S. ambassador to the United Nations Nikki Haley, who this week accused North Korean leader Kim of "begging for war".
"There is nothing more foolish than thinking we, a strong nuclear state, will endure this evil pressure aimed at overthrowing our state," the North's official news agency said in a commentary.
"Even if Nikki Haley is blind, she must use her mouth correctly. The United States administration will pay for not being able to control the mouth of their U.N. representative."
The United States wants the U.N. Security Council to impose an oil embargo on North Korea, ban its exports of textiles and the hiring of North Korean labourers abroad, and to subject leader Kim Jong Un to an asset freeze and travel ban, according to a draft resolution seen by Reuters on Wednesday.
China is by far North Korea's biggest trading partner, accounting for 92 percent of two-way trade last year. It also provides hundreds of thousands of tonnes of oil and fuel to the impoverished regime.
China's economic influence has been felt by South Korea as well. The two countries have been at loggerheads over South Korea's decision to deploy a U.S. anti-missile system, the Terminal High Altitude Area Defense, which has a powerful radar that can probe deep into China.
Shares in South Korean automaker Hyundai Motor and key suppliers slid on Friday on worry over its position in China after highly critical Chinese state newspaper comments.
The military section of China's Global Times newspaper on Thursday referred to THAAD as "a malignant tumour".
(Additional reporting by Nobuhiro Kubo in TOKYO and Hynjoo Jin in SEOUL; Writing by Lincoln Feast; Editing by Robert Birsel and Nick Macfie)