SEOUL, April 18 (UPI) -- South Korean government officials are saying a fifth North Korea nuclear test could "happen at anytime," and that the military is prepared to deal with Pyongyang's provocations.
South Korean President Park Geun-hye told reporters assembled at the presidential Blue House that North Korea could conduct a test to circumvent its isolation and strengthen its authority, local news service Newsis reported.
"Our internal readiness is important," Park said.
In a separate press conference Monday, defense ministry spokesman Moon Sang-kyun said activities at North Korea's Punggye-ri nuclear site indicated there is a possibility of an underground nuclear test.
"Given recent [North Korea] movements, an underground nuclear test is likely," Moon said.
Park said Monday the recent defection of 13 North Korean restaurant workers in China and the enforcement of the latest round of United Nations Security Council sanctions against Pyongyang in Europe, the United States and Japan are "showing their effects."
"As expected, North Korea is stepping up its provocations with tests of its nuclear weapons and missiles, and disruption of GPS signals," Park said.
In late March, North Korea launched cyberattacks that affected the South's border regions, producing electronic jamming signals, according to Seoul's science ministry.
The disruptions can affect plane navigation and can cause mobile phones to malfunction.
The South Korean president said solidarity between different political parties is key for the sake of "internal security and inter-Korea issues."
Park's ruling conservatives lost the parliamentary majority during elections last Wednesday – raising the possibility the South's North Korea policy could shift with the new tide in domestic politics.