The signing of a renegotiated free-trade agreement between the US and the Republic of Korea is spurring optimism that export markets for American farm goods won't shut down and may even expand. US President Donald Trump and his ROK counterpart Moon Jae-in signed the agreement Monday on the sidelines of the United Nations General Assembly in New York, the first major trade deal the US president has forged amid rising trade tensions. The ROK is the sixth-largest export market for US agriculture, buying $6.9 billion worth of farm goods last year, according to the American Farm Bureau Federation. "Securing export markets for our products is critical, and we encourage the administration to continue to push for conclusion of other trade agreements." Those include pacts with China, Mexico and Canada and looking to rejoin the Trans-Pacific Partnership, an agreement Trump pulled the US out of as soon as he took office.