North Korea says the onus is on the United States to change its "hostile policy" as the two countries begin a second day of talks aimed at defusing a nuclear crisis.
A report in the official Korean Central News Agency says the US-led war on Iraq showed that other countries needed "a strong physical deterrent force to protect" their sovereignty.
"The US should show its political will to make a bold switchover in its hostile policy toward [North Korea] and prove it in practice. This is the master key to making the talks fruitful," according to the report, which is considered to reflect official policy.
Envoys from Washington and Pyongyang have been meeting face to face this week for the first time since the crisis flared up last October.
The KCNA report said relations between the two countries had reached "rock bottom" after US President George W Bush called North Korea part of an "axis of evil" with Iran and pre-war Iraq.
Pyongyang's unease is likely to have been exacerbated by reports just a few days ago of a leaked memo from the US defence secretary, urging the removal of the current leadership in Pyongyang, says the BBC's Caroline Gluck in Seoul.
Negotiators on both sides have refused to comment on the progress of the talks. But the discussions are unlikely to result in a dramatic breakthrough, our correspondent adds.
The last time the two sides negotiated a nuclear deal, in 1994, the talks lasted 19 months.
North Korea's fuel rods could be used to make nuclear bombs
This meeting - which is taking place in Beijing - is expected to last until Friday.
Analysts stressed that the talks were aimed principally at breaking the silence between North Korea and the US.
The talks are being led by the US Assistant Secretary of State for East Asian affairs, James Kelly, and the deputy director general of North Korea's American Affairs Bureau, Li Gun.
The Beijing meeting represents a breakthrough in a dangerous six-month impasse over the North's nuclear programme.
Oct 2002 - US says N Korea "admits" secret nuclear programme
Nov 2002 - US-led decision to halt oil shipments to N Korea
Dec 2002 - N Korea expels two nuclear watchdog's inspectors
Jan 2003 - N Korea says it is withdrawing from Nuclear Non-Proliferation Treaty
Feb 2003 - N Korea "restarts" Yongbyon nuclear plant
Apr 2003 - N Korea ends insistence on direct talks with US
The US wants to persuade North Korea to close down its nuclear programmes, while the North wants assurances the US will not attack.
But tensions ahead of the talks remained high. North Korean fighter jets have begun long-distance training, South's Defence Ministry said on Wednesday.
They were monitoring US and Russian surveillance planes, the South Koreans said.
South Korea and Japan both hope to join the discussions at a later stage.
Their absence at the initial meeting was seen as a concession to the North, which demanded one to one talks with Washington. But the US is keen to include the North's neighbours in discussions.
The last time James Kelly held talks with a North Korean delegation, he accused them of pursuing a clandestine nuclear weapons programme, sparking the crisis in October.
President Bush later suspended oil aid shipments under a 1994 agreement designed to prevent Pyongyang from developing nuclear weapons.
Mr Kelly's October comments were an early sign of crisis
In December, North Korea restarted its nuclear facilities, expelled United Nations inspectors and withdrew from the Nuclear Non-Proliferation Treaty (NPT).
Last week North Korea announced that it was already reprocessing its spent fuel rods - the step necessary to produce weapons-grade plutonium.
That statement was amended on Monday to read that the North was "successfully going forward to reprocess" the 8,000 rods.
This new statement appears to fit with Western and Asian intelligence assessments that the reprocessing plant at the Yongbyon nuclear plant is not yet operational.