The unexpected visit by a high-ranking North Korean delegation on Saturday may have paved the way for a second round of high-level talks later this month or early November but, as is normally the case with North Korea, nothing is guaranteed.

As if to prove this point, a North Korean patrol boat on Tuesday morning crossed into South Korean territory in the West Sea and opened fire, according to the Defense Ministry. North and South Korean patrol boats exchanged fire briefly before the North Korean vessel retreated 10 minutes later.

The North Korean military’s latest border incursion, which took place shortly after Saturday’s agreement on high-level talks, is a reminder that Pyongyang remains as unpredictable as ever.

President Park Geun-hye must have had the unpredictability of North Korea on her mind when she told her top aides Monday to make efforts to ensure that the high-level contact leads to regular inter-Korean dialogue.

Since the highly unusual visit by North Korea’s top delegation, the Park administration has sought to lower expectations of a breakthrough in South-North relations. Unification Minister Ryoo Kihl-jae on Sunday tried to downplay talk of a sudden reconciliation. The next day, the Unification Ministry spokesperson said sanctions can be lifted only after North Korea takes a “responsible step that the South Korean people accept.”

The administration appears to be containing the growing sentiment, even among the ruling Saenuri Party members, that it is time to discuss lifting the May 2010 sanctions as they have outrun their usefulness. North Koreans have repeatedly demanded the lifting of the sanctions that were imposed on Pyongyang following its sinking of South Korea’s naval vessel the Cheonan.

Tuesday’s incident may further harden Park’s position that lifting sanctions is not possible without acceptable action by the North first and bodes ill for future talks.

In suddenly dispatching Hwang-Pyong-so, his second man; Choe Ryong-hae; and Kim Yang-gon to Incheon, North Korea’s Kim Jong-un provided the drama for which North Korea is well-known. Yet, there were few concrete results ― no letter for Park or meeting with Park ― except an agreement for a second round of high-level talks.

The ball is in the South Korean court now and the government must seize the opportunity to improve inter-Korean relations. In the meantime, both the South and the North would do well to refrain from provocations.