North Korea does not appear close to conducting a nuclear or missile test despite its continued preparations, a South Korean minister said Wednesday after a purge in Pyongyang sparked fears of aggression.

"Preparations have been made continuously... but I don't think a nuclear test or long-range missile launch is imminent," Unification Minister Ryoo Kihl-Jae told a parliamentary committee.

Ex-NBA star Dennis Rodman does not represent the U.S. government, a U.S. official insisted Tuesday, as he prepares to return this week to Pyongyang only days after the execution of a former North Korean official.

State Department spokeswoman Marie Harf stressed that Washington was focused on working with allies to rein in North Korea's nuclear program.

Massed ranks of military and party leaders pledged complete loyalty to North Korean leader Kim Jong-Un Tuesday on the second anniversary of his father's death, at a time of growing concern over the regime's stability.

The vows of obedience, at an elaborate gathering in Pyongyang honoring Kim's father and former supremo Kim Jong-Il, followed the shock execution last week of the young leader's uncle and one-time political mentor Jang Song-Thaek.

Thousands of North Korean propaganda leaflets fell Monday on a frontline South Korean island, warning of an attack on soldiers stationed there, a report said.

A South Korean marine unit based on Baengnyeong Island in the Yellow Sea had collected the leaflets which were carried across the border, Yonhap news agency said.

Washington called for a united front against North Korea after the "ominous" execution of leader Kim Jong-Un's uncle as South Korea put its forces on alert for any "provocations" from its nuclear-armed neighbor.

The warning came as thousands of North Korean troops marched in Pyongyang to pledge their loyalty to the young leader ahead of commemorations Tuesday to mark the second anniversary of the death of Kim's father and longtime leader Kim Jong-Il.

South Korean President Park Geun-Hye warned Monday of possible "reckless provocations" by North Korea after the shock execution of leader Kim Jong-Un's uncle, calling for the military to step up vigilance.

Pyongyang executed Jang Song-Thaek -- Kim's powerful uncle and political regent -- last Thursday, charging him with corruption and plotting to overthrow the state.

The execution of the North Korean leader's uncle is "an ominous sign" raising concerns about instability in a nation pursuing a nuclear arms drive, U.S. Secretary of State John Kerry warned Sunday.

Pyongyang on Thursday executed the uncle of North Korean leader Kim Jong-Un charging him with corruption and plotting to overthrow the state.

The aunt of North Korean leader Kim Jong-Un appears unscathed after the shock execution of her powerful husband, following fevered speculation that those close to the young supremo's uncle could be purged.

Kim Kyong-Hui, sister of late leader Kim Jong-Il, was named a member of the state funeral committee for a senior ruling party official who died on Friday, the state-run KCNA said late Saturday.

The United States has warned North Korea against any "provocative acts" following the shock execution of leader Kim Jong-Un's uncle, as the reclusive state campaigned to rally support behind the young supremo.

Washington also sought to step up talks with its Asian allies, voicing concern over regional stability after Jang Song-Thaek -- seen as Kim's political regent and the country's unofficial number two -- was executed on Thursday following a special military trial.

The United States is stepping up talks with Asian allies in the wake of North Korea's execution of the uncle of leader Kim Jong-Un for being a traitor, a top U.S. official said Friday.

While State Department spokeswoman Marie Harf refused to speculate on the reasons behind the purging of Jang Song-Thaek, she acknowledged that "stability on the Korean peninsula is very important to us."