North Korea fires missiles into sea as Pentagon chief visits region

North Korea has fired two surface-to-air missiles off its west coast, South Korea said on Thursday, with the latest in a string of short-range firings by the North coming shortly before the U.S. defense secretary arrived in the region.

The two short-range missiles were fired on Tuesday, South Korea's defense ministry said, and followed the launch on Friday of four short-range missiles off the west coast of North Korea.

U.S. Secretary of Defense Ash Carter arrived in Japan on Tuesday afternoon and traveled to South Korea on Thursday, where he was expected to discuss a response to North Korea's growing missile and nuclear threat.

“It's just a reminder of how tense things are on the Korean peninsula. That's the reason I’m going,” Carter told reporters at Yokota Air Base in Japan before departing for South Korea. “If it [the missile test] was a welcoming message to me, I’m flattered.”

A senior U.S. official described the missile test as a provocative act ahead of Carter's visit.

“Their missile inventory is growing, and their willingness to test those missiles appears to be growing as we've just seen today,” the official said, speaking on condition of anonymity.

U.S. military officials have said a sophisticated air defense system is needed in South Korea to counter the North's missile threat, although Washington has not made a formal proposal for deploying the THAAD missile defense system, and it is not officially on the agenda for Carter's visit.

“These are missiles launched, and it reinforces the missile defense preparations we’ve long had on the Korean peninsula and have here, by the way in Japan,” Carter said when asked if the latest North Korean missile launch underscores the need for THAAD deployment in South Korea.

China and Russia have both spoken out against placing THAAD, or Terminal High Altitude Area Defense, in South Korea.

The missile launches came as the leadership of King Jong Un convened its first parliamentary session of the year, a highly orchestrated event that North Korea watchers use to parse whether any discernable changes are at work within the country’s notoriously opaque power structure.

Three separate developments on Wednesday underscored the unease on the Korean Peninsula ahead of Carter’s visit to South Korea.

A North Korean defector living in South Korea said on Wednesday that he launched balloons carrying thousands of copies of the film "The Interview" to North Korea, despite protests from the isolated country and emailed death threats.

North Korea had earlier denounced the Hollywood comedy featuring a fictional plot to assassinate Kim Jong Un as an act of war and threatened retaliation if the film was released.

Lee Min-bok, a defector who left the North 20 years ago, said he had sent DVD copies of the film, dollar notes and anti-North leaflets in satchels tied to helium-filled balloons on four occasions, most recently on Saturday.

The launch of leaflets infuriates Pyongyang and has in recent months threatened to scuttle negotiations between the two Koreas. South Korean authorities have urged activists to refrain from launching leaflets on safety grounds, but say they have no legal grounds to stop them.

Separately, Pyongyang expelled an American aid worker for engaging in what it said was a conspiracy against the state, just weeks after the country ejected a German aid worker.

The North's official KCNA news agency said Sandra Suh had "produced pictures and videos with an aversion to the Republic under the disguise of 'humanitarianism' and used them" in a propaganda campaign against the country.

"Sandra Suh admitted ... her criminal activities and apologized, seeking generous forgiveness. Out of generosity, the related agency took into consideration her age and decided to expel her from its territory," KCNA said.

Los Angeles-based Wheat Mission Ministries says on its website that Sandra Suh began the group's work in 1989 to aid North Koreans, and that it was formally established as a non-profit organization in 2005. Whether Suh has any current affiliation with the group was not immediately clear, but Pyongyang often views aid workers or missionaries as foreign agents trying to encourage turmoil in the country.

Lastly, North Korea accused Mexico on Wednesday of illegally detaining one of its ships with some 50 crew and warned it would take "necessary measures" to release the vessel, which United Nations sanctions monitors say belongs to a blacklisted shipping firm.

The 6,700-ton freighter Mu Du Bong, which had come from Cuba, ran aground in July on a reef 8 miles northeast of Tuxpan in Mexico's Veracruz state. Mexico said the ship remains in the port of Tuxpan.

North Korea's Deputy U.N. Ambassador An Myong Hun told a small news conference on Wednesday that the Mu Du Bong was not linked to the blacklisted firm, Ocean Maritime Management Company, and therefore not subject to U.N. sanctions.

"We will take necessary measures to make the ship leave immediately," he added, without specifying what actions Pyongyang might take. North Korea is under U.N. sanctions due to its nuclear tests and missile launches. In addition to an arms embargo, Pyongyang is banned from trade in nuclear and missile technology and is not allowed to import luxury goods.

The U.N. Security Council last July blacklisted Ocean Maritime for arranging an illegal shipment on the Chong Chon Gang, which was seized in Panama and found to be carrying arms, including two MiG-21 jet fighters, hidden under thousands of tons of Cuban sugar.

Al Jazeera and Reuters