North Korea's news agency has warned the United States that it might bolster its so-called "self-defense" program, just as a key condition for nuclear disarmament appears to be nearly met.

The KCNA news agency Friday accused the U.S. of escalating an arms race with what it called a plan to build a global missile defense program.

A man talks on a mobile phone in front of the headquarters of Banco Delta Asia in Macau, 16 March 2007 file photo

North Korea has refused to honor a February nuclear disarmament agreement to shut down its Yongbyon nuclear reactors until it receives funds that have been frozen for months in a Macau bank.

The bank has released the funds, but it is unclear whether they have been completely transferred to a North Korean account in a Russian bank.

As the fund transfer process went on Friday, South Korea's top nuclear negotiator said that the path to disarming North Korea's nuclear weapons will be more difficult than resolving a banking issue.

On Thursday, officials in Macau said Banco Delta Asia has remitted most of the $25 million in funds the bank has held since 2005.

The money was frozen in 2005, after the United States alleged the Macau bank was tied to money laundering by North Korea.

Some information for this report was provided by AP and Reuters.