North Korea, while promising in negotiations to dismantle its nuclear materials production facility, has dragged out this work that could have been finished long ago, a senior U.S. general said.

Thus far, out of 11 steps to dismantle the Yongbyon reactor, eight of the steps thus far are complete, and a ninth step is about 80 percent finished, according to Army Gen. Walter L. Sharp, leader of multiple U.N. and U.S. commands in South Korea.

The job could have been finished long since, but Pyongyang is inching along, he told the Senate Armed Services Committee.

Meanwhile, other nations in the six-party talks aiming for denuclearizing the Korean Peninsula have been providing tons of fuel oil that the North demanded in exchange for dismantling the production facilities.

But North Korea has been turning to aggressive tactics, such as cutting communications with South Korea, and seizing Western video journalists near a border zone who were making a documentary for Current TV.

The North also has criticized just-ended U.S.-South Korean military exercises, accusing the two nations of planning to invade the North.

During those exercises, Russian military aircraft overflew the U.S. Navy aircraft carrier John C. Stennis on two consecutive days. American Navy F/A-18 fighter jets escorted the Russian planes until they left the area.

But at the same time, top Russian leaders are talking up the idea of a warming trend in U.S.-Russian relations, as Russian President Dmitry Medvedev prepares to meet with President Obama in two weeks during a Group of 20 Nations session.