MOSCOW -- A senior North Korean diplomat has returned home following her six-day trip to Russia, which included the two countries' first "strategic dialogue."

North Korean First Vice Foreign Minister Choe Son-hui told Korean reporters, "I had excellent talks with the Russian side this time," at Moscow's Sheremetyevo International Airport on Saturday evening as she awaited her Aeroflot flight to Beijing.

Arriving first at Vladivostok on Nov. 18, Choe, considered a key nuclear strategic aide to leader Kim Jong-un, went to Moscow the next day, where she talked with Russian foreign affairs and national defense officials. 

These included, most notably, the two countries' first strategic dialogue, held with Russian First Deputy Foreign Minister Vladimir Titov and Russian special envoy on North Korean nuclear issues Oleg Burmistrov at the Russian foreign ministry's guesthouse in downtown Moscow last Wednesday.

The strategic dialogue was launched after the first summit between North Korean leader Kim Jong-un and Russian President Vladimir Putin in April.

The same day, Choe held follow-up talks with Foreign Minister Sergei Lavrov at the Russian ministry headquarters in Moscow before holding another meeting with Vice Defense Minister Alexander Fomin on Thursday.

On Friday, she also sat down with Deputy Foreign Minister Igor Morgulov as her final talks with the Russian side.

The Russian foreign ministry later told the media that the two sides discussed in depth bilateral cooperation and the prospects of the bilateral relationship as well as security issues on the Korean Peninsula and in the Northeast Asia region.

Her trip comes amid Pyongyang's ramped up pressure on Washington to come up with a new proposal for their denuclearization negotiations that remain stalled since the breakdown of the Hanoi summit between Kim and US President Donald Trump in February.

As if to make the point, Choe pressed Washington on Friday into action over the stagnant denuclearization talks between the nations.

"If the United States does not take corresponding steps so that the chance of diplomacy on the Korean Peninsula disappears, I think the responsibility should lie squarely with the US," Choe told reporters following her meeting with Deputy Foreign Minister Morgulov. (Yonhap)