WASHINGTON — After three years of diplomatic deadlock, the Obama administration says it is open to holding preliminary talks with North Korea to probe its intentions and assess the prospects of ridding the country of nuclear weapons.

A senior South Korean envoy traveled to Washington and Beijing this past week as nations involved in long-stalled aid-for-disarmament negotiations consider their diplomatic options. Tensions have eased a little on the Korean Peninsula following the completion of annual U.S.-South Korean military drills.

But it remains unclear if a diplomatic overture to North Korea will even get to first base as the Asian nation appears intent on retaining its nuclear weapons. U.S. officials don’t believe the North has demonstrated a serious interest in re-engaging on the issue, and a spokesman at the North Korean diplomatic mission at the United Nations declined to comment on the question of re-engagement.

President Barack Obama has broken the ice with several other long-standing adversaries, like Iran, Cuba and Myanmar. In the case of Iran, the U.S. has joined with other world powers in negotiating a framework agreement to prevent Tehran from obtaining a nuclear weapon.

North Korea has gone far beyond that point. The North conducted its first nuclear test in 2006, and despite international sanctions intended to prevent Pyongyang from obtaining sensitive technology and starve it of funds, U.S.-based experts are forecasting that it could increase its nuclear arsenal from at least 10 weapons today to between 20 and 100 weapons by 2020.