WASHINGTON, -- Growing military cooperation among North Korea, Russia, China and Iran raises the possibility of "simultaneous conflicts with multiple nuclear-armed adversaries," a top US general warned Thursday.

Gen. Anthony Cotton, commander of US Strategic Command, made the remarks during a session of the Senate Armed Services Committee, stressing that his command will "always" be "ready to fight tonight."

"We are confronting not one, but two nuclear peers -- the Russian Federation and the People's Republic of China. This reality, combined by missile developments in North Korea, Iran's nuclear ambitions and the growing relationships amongst those nations, adds new layers of complexity to our strategic calculus," he said.

"It also raises the possibility of simultaneous conflicts with multiple nuclear-armed adversaries," he added.

His remarks came amid growing concerns about burgeoning military cooperation between Pyongyang and Moscow.

The United States has revealed that the North provided Russia with ballistic missiles, munitions and other pieces of military equipment for use in Ukraine, while in return, it is seeking assistance from Moscow, including fighter aircraft, surface-to-air missiles, armored vehicles and ballistic missile production equipment.

Cotton highlighted that he has been keeping close tabs on the growing ties between the North and Russia.

"That transactional relationship between Russia and the DPRK has manifested itself in different ways over the past eight months," he said, referring to the North by its official name, the Democratic People's Republic of Korea.

"We are looking at that differently on what that relationship actually is, what does the DPRK gain with that new relationship that they have with Russia," he said.

In a written statement submitted to the committee, Cotton raised the possibility of the North conducting a nuclear test to show its military muscle. Seoul officials have said that Pyongyang remains technically ready for another test while its timing may hinge on North Korean leader Kim Jong-un's strategic calculus.

"DPRK leadership recently declared that the country's status as a nuclear weapons state 'has now become irreversible,' and it is possible the DPRK will resume nuclear testing in order to demonstrate its capabilities," the commander wrote.

Cotton pointed out that the North views its nuclear arsenal as "a means to ensure regime survival and influence Republic of Korea and US forces in the area."

"The DPRK is developing and fielding mobile short-, intermediate-, and intercontinental-range nuclear capabilities that place the United States homeland and regional Allies and partners at risk," he said.

Despite concerns over growing military ties among the North, Russia, China and Iran, Cotton voiced confidence over his command's readiness.

"The men and women that represent US Strategic Command are ready to defend ... if strategic deterrence failure happens tonight, we are ready today."

At the same committee session, Gen. Stephen Whiting, commander of US Space Command, said that North Korea does not have a "space-enabled military today," but it has demonstrated an electromagnetic warfare capability that could have impact against US space systems.

"We are also very carefully watching their space systems," Whiting said, referring to the North's launch last year of what it claimed was a military reconnaissance satellite.

"Of course, they should not be launching it into space because of the UN resolutions that say they can't use ballistic missile technology for that. And so again, we are having to keep an eye on what they might be thinking of in the future," he added.

In a written statement, Whiting said that despite the North's frequent missile and satellite program failures, Pyongyang has demonstrated the ability to "sustain a high number of missile launches," and has fielded capable cyber and electronic warfare weapons that present "disruptive potential to the space domain."