SEJONG, South Korea (Reuters) -South Korea will seek an extension to the 90-day pause in U.S. tariffs that is set to expire next week, as negotiations are likely to continue past the deadline set between Seoul and Washington, a senior South Korean trade official said on Monday.

South Korea's new administration held its first senior-level trade talks with the U.S. last week, and a third round of working-level technical discussions since the two countries agreed in late April to craft a trade package reducing U.S. tariffs before the U.S. 90-day pause ends on July 9.

"It seems some countries will reach a deal by July 8, some might be granted an extension to continue negotiations, while others will decide if they want to continue negotiating under tariffs or not," the official told a briefing.

"We will do our best to be granted by July 8 an extension to continue negotiations," the official said, adding that the U.S. is expected to make a decision on a further extension on the day.

During the talks last week, the U.S. mainly raised issues related to South Korea's non-tariff barriers, as South Korea already imposes nearly zero tariffs on U.S. imports under a free trade agreement, the official said.

Other issues of foreign exchange rates and defence costs are being discussed via separate channels, the official said. Some 28,500 U.S. troops are stationed in South Korea as a deterrence to North Korea and U.S. President Donald Trump has often complained about the cost-sharing arrangement.

(Reporting by Jihoon Lee; Editing by Lincoln Feast.)