Top diplomats and defense chiefs from South Korea and the United States met Wednesday for unprecedented security talks in what many say is Washington's show of strong support for its Asian ally rattled by alleged torpedo attack from its wartime enemy.

The talks resulted in the announcement that fresh measures will be taken against the Democratic People's Republic of Korea (DPRK)' s procurement of nuclear materials, a strong warning against the country that unilaterally quit multilateral nuclear talks over its denuclearization in April 2009.

Inaugural talks

The so-called "two plus two" security talks, involving U.S. Secretary of State Hillary Clinton, Defense Secretary Robert Gates and their South Korean counterparts, were the first of its kind held between Seoul and Washington.

The talks, originally designed to highlight their six-decade- old alliance forged in the wake of the 1950-53 Korean War, carried particularly more weight as it came shortly after South Korea wrapped up its international diplomatic venture to censure the DPRK for the sinking of the warship Cheonan, which killed 46 South Korean sailors.

The United Nations Security Council issued a presidential statement that condemned the attack in March but stopped short of directly blaming Pyongyang, taking note of its insistence on its innocence. The DPRK, which previously threatened to wage an "all- out war" if it is punished, said it is "satisfied" with the result.

Analysts saw the talks partly as a means for Seoul and Washington, close allies that jointly pushed for international denunciation of Pyongyang at the UN, to open the first chapter of the post-Cheonan era while sending a strong message to the DPRK against further aggression.

Sanctions and drills

And the message seemed clear enough.

"Today, I'm announcing a series of measures to increase our ability to prevent North Korea (DPRK)'s proliferation, to halt their illicit activities that helped fund their weapons programs and to discourage further provocative actions," Clinton said in a joint press conference that followed the talks.

"We will implement new country-specific sanctions aimed at North Korea's sale and procurement of arms and related material and the procurement of luxury goods and other illicit activities," she added.

UN Security Council Resolutions 1718 and 1874, introduced in 2006 and 2008 after the DPRK conducted its first and second nuclear experiments, will also be more strictly imposed on Pyongyang, Clinton said.

While calling on the DPRK to abandon all its nuclear programs and its pursuit of nuclear weapons, the top U.S. diplomat said stalled six-party nuclear talks, aimed at ridding Pyongyang of its nuclear programs, "is not something we are looking at yet."

Meanwhile, Seoul and Washington are planning on a series of military drills, a show of combined military capabilities and a response to the deadly sinking of the Cheonan.

Gates, who arrived in Seoul on Monday, finalized details of joint exercises with his counterpart Kim Tae-young during a meeting a day ago. The first such drill involving the U.S. aircraft carrier USS George Washington will be staged on July 25 in waters off the east coast of the Korean peninsula, and more events are planned.

Adding more pressure to Pyongyang, the two countries also plan to join anti-proliferation drills on October 13 in waters off the South Korean port city of Busan to guard against proliferation of the weapons of mass destruction. Other countries in the Asia- Pacific region, including Japan, Australia and Singapore, will take part in the drills.