The easternmost South Korean islets of Dokdo are subject to the mutual defense treaty between South Korea and the United States, the foreign ministry said Thursday, suggesting that a foreign attack on the islets would lead to joint countermeasures.

"Our government's stance is that Dokdo is a territory under South Korea's administrative control as stipulated in the South Korea-U.S. Mutual Defense Treaty," foreign ministry spokesman Cho Tai-young said in a briefing.

Cho's comments indicate that South Korea and the U.S. would jointly react to any military action from abroad on the Dokdo islets as stipulated in the mutual defense treaty of territories of one another.

The comments came after U.S. President Barack Obama, now visiting Japan, vowed similar joint efforts with Tokyo over disputed islands between Japan and China.

Obama said the islands, called Senkaku by Tokyo and the Diaoyu by Beijing, are subject to the mutual defense treaty between Washington and Tokyo.

But it is unclear whether Obama would discuss Dokdo with South Korea when he visits here later this week, the spokesman said.

Dokdo has been a vexing source of diplomatic tension between South Korea and Japan, with Tokyo repeatedly laying claims to the islets.

Touching on the possibility of reaching a trilateral military information sharing pact between Seoul, Washington and Tokyo, Cho said, "I think there is a need (to come up with one) ... but our government stance is that it will decide on it after reviewing the domestic situation."

South Korea's previous attempt to sign the military intelligence sharing pact with Japan was suspended in mid-2012 as the government's steps taken secretly to forge the sensitive pact with the former colonial ruler inflamed public sentiment.

"As you know the push for a South Korea-Japan military information sharing pact was suspended after years of attempts ... the government would again seek it only after reviewing local conditions," he said. (Yonhap)