( CNN ) -- If North Korea continues with its controversial missile and nuclear tests , it `` will move closer '' to its objective of reaching the United States with nuclear weapons , according to a Pentagon report . During recent heightened tensions on the Korean Peninsula , Pyongyang repeatedly threatened the possibility of nuclear attacks against the United States and South Korea , prompting questions on the progress of its weapons program . North Korea 's secretiveness has made it hard for Western intelligence agencies to gauge exactly what is going on inside its research facilities . Many clues have come from the regime 's large-scale tests such as the long-range rocket launch in December and the underground nuclear detonation in February . The Pentagon 's annual report to Congress on Thursday provided an overview of the military threat posed by North Korea , but it did n't say how long it believed it would take the isolated , Stalinist state to develop a fully operational nuclear missile capable of reaching the U.S. mainland . It described North Korea 's ballistic missile program as `` ambitious '' and said that `` the pace of its progress will depend , in part , on how many resources it can dedicate to these efforts and how often it conducts tests . '' Doubts over North 's capabilities . A sign of differing views on North Korea 's nuclear missile capabilities among U.S. intelligence agencies emerged last month . Addressing the House Armed Services Committee , a congressman read out an excerpt from a report by the Pentagon 's intelligence arm that said it believed with `` moderate confidence '' that the North had nuclear weapons that could be delivered by ballistic missiles , albeit with low `` reliability . '' But after the disclosure of that assessment from the Defense Intelligence Agency ( DIA ) , top U.S. officials including President Barack Obama said the U.S. government did n't think North Korea was yet able to fit a nuclear warhead on a ballistic missile . The Pentagon report Thursday included no reference to the DIA excerpt , which did n't specify the range of the ballistic missiles that it was talking about . The report said that the type of long-range rocket that North Korea launched in December to put a satellite in orbit `` could reach parts of the United States if configured as an intercontinental ballistic missile ( ICBM ) capable of carrying a nuclear payload . '' But it noted that `` a space launch does not test a re-entry vehicle ( RV ) , without which North Korea can not deliver a weapon to target from an ICBM . '' The December launch and the display in April 2012 of an untested but road-mobile intercontinental ballistic missile help underscore `` the threat to regional stability and U.S. national security posed by North Korea , '' according to the report . Like father , like son . Its authors said they did n't expect much change under North Korean leader , Kim Jong Un , from the strategy shaped by his father , Kim Jong Il , who died in December 2011 . The focus of that approach , they said , includes `` coercive diplomacy to compel acceptance of its diplomatic , economic and security interests ; development of strategic military capabilities to deter external attack ; '' and challenges to South Korea and the U.S.-South Korean alliance . Under Kim Jong Un , North Korea has so far continued the pursuit of more advanced nuclear and missile technologies , which according to the report , the regime sees as `` essential to its goals of survival , sovereignty and relevance . '' The long-range rocket launch in December and underground nuclear test in February prompted international condemnation and tougher U.N. sanctions . Those measures were followed by intensified threats from Pyongyang , during which the United States said it would deploy additional missile defenses on its West Coast . The Pentagon report also highlighted the murkiness of the North 's decision-making processes -- a particular concern during periods of heightened tensions like the past few months . `` Although North Korea is unlikely to attack on a scale that it assesses would risk the survival of its government by inviting overwhelming counterattacks by the ROK or the United States , we do not know how North Korea calculates this threshold of behavior , '' the report said , using the abbreviated form of South Korea 's official name , the Republic of Korea . `` North Korea 's use of smallscale attacks and provocative acts leaves much room for miscalculation that could spiral into a larger conflict , '' it said . CNN 's Alison Harding contributed to this report .
A Pentagon report to Congress gives an overview of North Korea 's military strategy . It discusses the North 's progress toward developing a nuclear missile . The pace of development will depend on the amount of money allocated , it says . The report 's authors say they saw little change in strategy under Kim Jong Un .