The United States will send South Korea two B-1B Lancer bombers this week in a display of force against North Korea amid Pyongyang's growing missile and nuclear threats, Yonhap News reported Tuesday. The move came as North Korean leader Kim Jong Un oversaw the test and launch of a new military satellite Tuesday in a sign the country is preparing a long-range rocket launch.

"Here we are a few weeks after the fifth nuclear test and they are testing an engine which, according to North Korea, is a much more powerful single engine," said Al Jazeera's Harry Fawcett, reporting from the South Korean capital Seoul.

The Lancer can fly low and fast with a large payload. "The multi-mission B-1 is the backbone of America's long-range bomber force. It can rapidly deliver massive quantities of precision and non-precision weapons against any adversary, anywhere in the world, at any time," the Air Force states on its website.

Kim Yong-kyu, a spokesman for United States Forces Korea, would not confirm the media reports, telling Yonhap News the USFK, "does not discuss operational matters." But USFK Commander Gen. Vincent K. Brooks urged the U.S. last week to step up its actions in the violatile region. 

"North Korea's nuclear test is a dangerous escalation and poses an unacceptable threat. The United States has an unshakable commitment to defend allies in the region and will take necessary steps to do so," he said at the time. 

North Korea carried out its fifth nuclear test last week, prompting the U.S. to bolster its national security efforts in the region by flying four U.S. F-16 fighter jets last week alongside four South Korean F-15K over the peninsula.

Kim was quoted Tuesday telling state media that the satellite launch must be completed as soon as possible, amid "the enemies' harsh sanctions and moves to stifle," in an apparent reference to the United States and South Korea.

Norea Korea's nuclear ambitions also saw U.S. President Barack Obama and Chinese Premier Li Keqiang discuss during a United Nations Security Council meeting in New York Monday possible U.N. sanctions against the isolated nation.

"Both leaders condemned North Korea’s Sept. 9 nuclear test and resolved to strengthen coordination in achieving the denuclearization of the Korean Peninsula, including by invigorating cooperation in the United Nations Security Council and in law enforcement channels on North Korea," a White House statement said.