U.S. ally South Korea has long faced threats from North Korea.
The detention of 475 workers, more than 300 of them South Korean, in the Sept. 4 raid has caused confusion, shock and a sense of betrayal among many in the U.S.-allied nation.
President Donald Trump is willing to meet with North Korean leader Kim Jong Un, he told his South Korean counterpart during a meeting on Monday
Lee, elected in June, began by praising one of Trump's pet projects: presidential interior design.
Trump announced a new trade deal with South Korea, which calls for 15% tariffs on goods from there, after the country scrambled to secure an agreement ahead of the Friday deadline.
In South Korea, all able-bodied men aged 18 to 28 are required by law to perform 18-21 months of military service under a conscription system meant to deter aggression from rival North Korea.