North Korea's test-firing of short-range missiles may have been to provoke South Korea, an official in Seoul said Friday.

South Korean Defense Ministry spokesman Won Tae-jae said leaders thought the firing was made in "regard to the relations" between the two countries, South Korean news agency Yonhap reported.

"Unless it is a mid-range missile or a longer-range one, we believe it is aimed at South Korea," Won said.

Reports that North Korea was preparing to test-fire mid- or long-range missiles Saturday at the United States are not considered serious, military leaders in Seoul said. Saturday is Independence Day in the United States.

"This is only speculation," Won said. "We don't see it as carrying military significance."

The U.N. Security Council last month sanctioned North Korea for its latest underground nuclear test. The North fired four short-range ground-to-ship missiles into the East Sea Thursday despite the resolution, which also bans testing such weapons.