"The two countries have great potential for broadening substantive cooperation in the trade, investment and energy fields," Moon said in his opening statement, which pool reporters were allowed to cover.

In response, the Bulgarian prime minister expressed hope for closer ties on the education of a skilled workforce as well as trade and economy.

"(We) hope for a lot of cooperation in the education sector," he told Moon. "Investment, energy cooperation and all other things are of importance but the basis is talented people. So I think how we create high-quality manpower is a very important issue."

For Bulgaria, he added, South Korea is a strategic partner and a "strategic investor."

Two-way trade totaled $353 million in 2018, which Borissov said is larger than that between Bulgaria and Japan.

In a post-summit press release, Cheong Wa Dae said the two sides have agreed to "expand mutually beneficial, forward-looking cooperation in trade, investment, energy, infrastructure, national defense, the defense industry, culture and education."

Moon requested Sofia's cooperation so that South Korean companies can take part in its nuclear reactor and arms acquisition projects.

They also agreed to step up partnerships between their nations on renewable energy, such as electric vehicle batteries and other automobile parts, according to Cheong Wa Dae.

The prime minister reaffirmed the Balkan nation's firm support for the Korea peace process, it added.

Borissov also invited Moon to visit his country next year.

Separately speaking to reporters later, Cheong Wa Dae spokesperson, Ko Min-jung, said Moon and Borissov had "quite a lot of conversations" on agricultural issues, which were not touched on in the press statement.

The prime minister said Bulgaria is known for high-quality dairy goods and livestock products that are "beloved" by neighboring countries, Ko said, quoting Moon as replying, "I hope for the strengthening of cooperative relations in the agricultural field."

Borissov arrived in Seoul on Wednesday for a three-day trip, becoming the first Bulgarian prime minister to make an official visit to South Korea. (Yonhap)