South Korean foreign minister says she was 'surprised' when Trump said joint military exercises would end

South Korea's foreign minister said she was "surprised" after President Donald Trump announced that U.S. - South Korea joint military exercises would end and - when asked by ABC News whether North Korean leader Kim Jong Un could be trusted - replied that "trust is a tricky word."

South Korea was left reeling this week after Trump announced following his summit with Kim that the exercises, which have taken place routinely for years on the Korean Peninsula, would stop.

"Well, I have to say, yes, we were surprised," the minister, Kang Kyung-wha, told ABC News' James Longman in an interview Thursday in the South Korean capital, Seoul.

"But I think, you know, you can’t script these things," she said. "The [U.S.] president said it judging by the understanding that he had and his judgment of his counterpart across the table at the historic summit, and we will see what has gone into this statement and that, in fact, is being discussed with my counterparts in our military with yours."

Trump became the first sitting U.S. president to meet with a North Korean leader when he and Kim held a summit in Singapore on Tuesday. They signed a declaration which did not directly address the exercises.

Following his meetings with Kim, Trump told ABC News chief anchor George Stephanopoulos in an interview Tuesday that he has suggested ending the war games, calling them "very provocative."

The announcement unsettled the South and raised questions about exactly what exercises would come to an end. The United States has 28,500 troops stationed in the South and conducts joint military exercises there throughout the year.

"It is clearly his desire to reinforce the momentum for dialogue that he has now created" with Kim, Kang said, referring to Trump. "I think the issue of the exercises is a key issue for our alliance, and whatever we do about that will ensure that the very strong combined defense posture of the alliance is maintained.

"We will discuss it as we always do these annual exercises military level," she added.

Trump also said this week that he trusted Kim. Asked whether or not the North Korean leader could be trusted, Kang said it was complicated.

"Trust is a tricky word," she said, "but I think my president has confidence that he has decided and he is determined to deliver on the new course that he has set for his own country."

South Korean President Moon Jae-in has embraced engagement with the North, holding his own summit with Kim at the Koreas' shared border in April.

Trump told ABC News chief anchor George Stephanopoulos in an exclusive interview on Tuesday, following his meetings with Kim, that he trusted the North Korean leader.

"I do trust him, yeah," Trump said. "Maybe in a year you’ll be interviewing and I'll say I made a mistake. It's possible. We’re dealing at a high level, a lot of things can change a lot of things are possible."