UPDATE 1-Trump says may hold up S.Korea trade deal until after deal with N.Korea

N.Korea@ (Adds quote from Trump, background on trade deal)

RICHFIELD, Ohio, March 29 (Reuters) - U.S. President Donald Trump said on Thursday he may hold up a trade agreement reached this week with South Korea until after a deal is reached with North Korea on denuclearization.

"I may hold it up until after a deal is made with North Korea," Trump said in a speech. "It's a very strong card," he added.

Senior U.S. officials have expressed concerns privately that South Korea is the weak link in the U.S. alliance between South Korea and Japan and could be too quick to seal a deal with North Korea.

Trump agreed this month to accept an invitation to meet with North Korea's Kim Jong Un.

"We're moving along very nicely with North Korea. We'll see what happens. Certainly the rhetoric has calmed down just a little bit," Trump said on Thursday.

The United States and South Korea agreed to revise their six-year-old trade pact with a side deal to deter competitive currency devaluation by Seoul and with concessions for U.S. autos and pharmaceutical companies, Trump administration officials said on Tuesday. (Reporting by Steve Holland; writing by Eric Beech; editing by Jonathan Oatis and James Dalgleish)