Second US aircraft carrier enters western Pacific amid North Korea tensions

A second U.S. Navy aircraft carrier strike group entered the western Pacific, the Navy's 7th fleet announced Tuesday, amid an increasing war of words between the United States and North Korea.

USS Theodore Roosevelt – the “Big Stick” – left its San Diego home port earlier this month on a scheduled deployment to the West Pacific and Persian Gulf. It will now join the USS Ronald Reagan strike group off the Korean Peninsula.

In this April 13, 2015 photo released by U.S. Navy Media Content Services, helicopters fly from the aircraft carrier USS Theodore Roosevelt during a vertical replenishment with the aircraft carrier USS Carl Vinson in the Gulf of Oman. The U.S. Navy has dispatched USS Theodore Roosevelt toward the waters off Yemen to join other American ships prepared to intercept any Iranian vessels carrying weapons to Houthi rebels, U.S. officials said on Monday. (Mass Communication Specialist 2nd Class Scott Fenaroli/ U.S. Navy Media Content Services via AP)

Helicopters fly from the aircraft carrier USS Theodore Roosevelt, which is headed to the Korean Peninsula.  (U.S. Navy)

The carrier is expected to make its way to the Persian Gulf to relieve the aircraft carrier USS Nimitz.

"Entering 7th Fleet is an exciting opportunity to integrate with other U.S. Navy units in the [area of operations], as well as operate with our partners and allies in the region," said Rear Adm. Steve Koehler in a statement. "We look forward to continued partnerships that lead to mutual security and common views about operating at sea.”

It is rare to have two U.S. Navy aircraft carriers stationed in the region.

The aircraft carrier USS Ronald Reagan (CVN 76) is escorted into Busan port, South Korea, after completing a joint drill with the South Korean military, Saturday, Oct. 21, 2017. U.S. naval commanders on Saturday reiterated Washington's "ironclad" commitment to defend South Korea against North Korean threats as the American nuclear-powered aircraft carrier visited a South Korean port following a joint naval drill. (Jo Jung-ho/Yonhap via AP)

The aircraft carrier USS Ronald Reagan is escorted into Busan port, South Korea, after completing a joint drill.  (AP)

The last time it happened was back in June when the Carl Vinson and Reagan strike groups were together for a few days in the Peninsula for training purposes – but it marked the first time since the 1990s that two U.S. carriers were near the Korean Peninsula.

"USS Theodore Roosevelt is prepared to carry out the full spectrum of possible missions, from humanitarian relief to combat operations," Capt. Carlos Sardiello, Theodore Roosevelt's commanding officer, said in a statement. "When a carrier leaves on deployment, we have to be ready for anything."

The deployment comes as the U.S., Japan and South Korean maritime forces are conducting a trilateral exercise aimed at improving ballistic missile defenses. 

FILE - This undated file photo distributed by the North Korean government shows North Korean leader Kim Jong Un, center, at an undisclosed location in North Korea. The world is wondering if North Korea’s next nuclear test will involve a nuclear missile screaming over Japan after the North said it may test a hydrogen bomb in the Pacific Ocean. Independent journalists were not given access to cover the event depicted in this image distributed by the Korean Central News Agency via Korea News Service. The content of this image is as provided and cannot be independently verified. (Korean Central News Agency/Korea News Service via AP, File)

North Korean leader Kim Jong Un has sped up progress on his nuclear and missile programs.  (AP)

"The exercise will employ tactical data link systems to exchange track data among all the participating ships," the Navy said

On Monday, Japan's defense minister asserted North Korea's nuclear and ballistic missile capabilities have grown to an "unprecedented, critical and imminent" level, requiring "different responses" to the threat.

The minister, Itsunori Onodera, said the rising threat compels his country to endorse the U.S. view that "all options" must be considered, which President Trump says includes possible military action. Japan was alarmed by North Korea twice launching ballistic missiles over Japanese territory, in August and in September.

Onodera's comments, made through an interpreter, came at the outset of a so-called trilateral meeting in the Philippines with U.S. Defense Secretary Jim Mattis and South Korea's defense minister, Song Young-moo.

"The country has steadfastly improved it nuclear and missiles capability," Onodera said. He added: "The threat posed by North Korea has grown to the unprecedented, critical and imminent level."

"Therefore, we have to take calibrated and different responses to meet that level of threat," he said, without elaborating on what "different" responses Japan favors.

Mattis was somewhat more reserved in his remarks than Onodera, although he did slam Pyongyang for defying U.N. Security Council resolutions against its nuclear and ballistic missile programs.

"North Korea's provocations threaten regional and global security," he said.

Fox News' Lucas Tomlinson and the Associated Press contributed to this report.