Julianne Smith, the U.S. permanent representative to the North Atlantic Treaty Organization, speaks to a group of reporters in central Seoul on Thursday. Yonhap

South Korea's recent arms exports to Poland have helped the North Atlantic Treaty Organization (NATO) address the alliance's military capabilities reduced by its support to Ukraine in the war against Russia, the U.S. envoy to NATO said Thursday.

Last year, Warsaw signed a series of deals to buy South Korean weapons systems, such as K-2 main battle tanks, K9 self-propelled howitzers, Chunmoo multiple rocket launchers and FA-50 light attack aircraft.

"Because of the ongoing support across NATO to provide military support to Ukraine, we have as a result of that support encountered some shortfalls inside NATO capitals," Amb. Julianne Smith told a group of reporters in Seoul.

Smith, however, noted the "budding" ties between South Korea and Poland have helped address such challenges.

"This is of tremendous assistance when industry in the Republic of Korea can assist with some of those backfill challenges through the sale of military capabilities," she said, using South Korea's official name.

"That's a really important contribution that is not attached directly to what's happening in Ukraine, but it has helped us address a challenge that has come as a result of our collective assistance to Ukraine," she said.

Smith flew into Seoul on Wednesday for a three-day visit along with counterparts from seven other NATO members, including Britain, Italy and Poland.

When asked about South Korea possibly providing lethal arms support to Ukraine directly, Smith said NATO respects each country's sovereign decisions in their support to Ukraine, noting that some NATO members are primarily providing Ukraine with humanitarian and economic support.

Earlier this week, The Washington Post reported that South Korea indirectly provided more 155-mm artillery shells to Ukraine this year than all European countries combined. Seoul has maintained that its policy against directly providing lethal weapons to Ukraine remains unchanged.

Regarding her visit to South Korea, Smith noted "shared security challenges" NATO and Seoul face, such as the recently deepening cooperation between Pyongyang and Moscow.

"Both our friends in the ROK and the NATO alliance are looking very closely at the evolving relationship between the DPRK and Russia," she said. "We have both been troubled to see the increased military assistance that is being funneled from the DPRK to Russia."

ROK stands for the Republic of Korea, while DPRK stands for the North's official name, the Democratic People's Republic of Korea.

South Korea, the United States and Japan have accused North Korea of delivering weapons to Russia, which they said are being used for its war on Ukraine. (Yonhap)