South and North Korea are likely to see their strained relations last at least until May when a bilateral summit could be expected on the sides of a World War II anniversary celebration in Russia, experts on North Korean affairs predicted Sunday.

The experts pointed out that the rival Koreas have missed out on "their golden opportunity" for fence-mending, created at the beginning of the new year when they showed eagerness to improve relations.

In an effort for a breakthrough in strained inter-Korean relations, Seoul proposed in late December the two countries hold high-level talks to discuss pending issues, including arranging a reunion of families separated by the 1950-53 Korean War.

In his New Year's message, North Korean leader Kim Jong-un alluded to possible acceptance of the proposal, fueling hopes for a breakthrough in the long-fractured inter-Korean ties.

The hopes, however, have fast faded as the two countries bickered over joint Seoul-Washington military exercises and cross-border anti-Pyongyang leaflet campaigns by South Korean activists. The North has not answered to Seoul's December offer so far.

The North Korea experts said the two Koreas may have to ride out the soured mood before finding another opportunity for fence-mending in May.

In May, North Korean leader Kim Jong-un is reportedly planning to attend a ceremony in Moscow, Russia to celebrate the 70th anniversary of what was then the Soviet Union's victory in World War II in 1945.

The North Korean leader's expected debut to the international diplomatic scene could provide a breakthrough in the country's foreign relations, including a possible summit with President Park Geun-hye on the occasion, experts said.

Before the Moscow event, however, the North may continue to step up military provocations in response to the planned joint military drills between South Korea and the United States, according to the experts.

The allies are set to kick off their Key Resolve and Foal Eagle war exercises next month on the Korean Peninsula as part of annual efforts to check and upgrade interoperability.

The North has already begun its habitual protest against the annual joint drills, having test-fired short-range missiles in the near sea.

Mindful of the need for better foreign relations and improved economic situation, however, the communist country may not resort to extreme military provocations such as the test-firing of long-range missiles or a nuclear detonation, the North Korea experts noted.

"Rather than taking high-level military provocations like a nuclear test, the North is highly likely to carry out mid- to low-level provocations including firing of short-range missiles and violating the Northern Limit Line (sea border) in the West Sea,"

Yang Moo-jin, professor at the University of North Korean Studies, said.

"Looking back on the situation on the peninsula in January and February, it seems that South and North Korea as well as the U.S.failed to find common ground because they all went their way alone," the North Korea expert noted.

Another expert also advised that Seoul needs to be more flexible in dealing with North Korea in order to attain a breakthrough in the long-strained inter-Korean relations.

"For the sake of inter-Korean dialogue, (Seoul) needs to take care of what is deemed as insults to North Korea's highest dignity and recognize the North as a political entity entitled to be a dialogue partner," Chang Yong-suk, a researcher at Institute for Peace and Unification Studies at Seoul National University, said. (Yonhap)