Anchorage, Sep 18 (AP) The US military has moved about 130 soldiers along with mobile rocket launchers to a desolate island in the Aleutian chain of western Alaska amid a recent increase in Russian military planes and vessels approaching American territory.

Eight Russian military planes and four navy vessels, including two submarines, have come close to Alaska in the past week as Russia and China conducted joint military drills. None of the planes breached US airspace and a Pentagon spokesperson said Tuesday there was no cause for alarm.

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“It's not the first time that we've seen the Russians and the Chinese flying, you know, in the vicinity, and that's something that we obviously closely monitor, and it's also something that we're prepared to respond to,” Pentagon spokesperson Maj. Gen. Pat Ryder said at a news conference.

As part of a "force projection operation,” the Army on September 12 sent the soldiers to Shemya Island, some 1,200 miles (1,930 kilometres) southwest of Anchorage, where the US Air Force maintains an air station that dates to World War II. The soldiers brought two High Mobility Artillery Rocket Systems, or HIMARS, with them.

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US Sen. Dan Sullivan, R-Alaska, said the US military also deployed a guided missile destroyer and a Coast Guard vessel to the western region of Alaska as Russia and China began the “Ocean-24” military exercises in the Pacific and Arctic oceans September 10.

The North American Aerospace Defence Command said it detected and tracked Russian military planes operating off Alaska over a four-day span. There were two planes each on September 11, September 13, September 14 and September 15.

The planes operated in the Alaska Air Defence Identification Zone, a zone beyond US sovereign airspace, but within which the US expects aircraft to identify themselves, NORAD said.

The Russian Embassy in the US did not immediately respond to an email seeking comment.

NORAD has said the number of such incursions has fluctuated yearly. The average was six to seven intercepts a year. Last year, 26 Russian planes came into the Alaska zone, and so far this year, there have been 25.

Often in such encounters, the military provides photos of the Russian warplanes being escorted by either US or Canadian planes, such as during a July 24 intercept of two Russian and two Chinese planes. However, none was released in the past week and a NORAD spokeswoman, Canadian Maj. Jennie Derenzis, declined to say whether jets were scrambled to intercept the Russian planes.

The US Coast Guard said Sunday its homeland security vessel, the 418-foot (127-metre) Stratton, was on routine patrol in the Chukchi Sea when it tracked four Russian Federation Navy vessels about 60 miles (96 kilometres) northwest of Point Hope, Alaska.

The Russian vessels, which included two submarines, a frigate and a tugboat, had crossed the maritime boundary into US waters to avoid sea ice, which is permitted under international rules and customs.

Two years ago, a US Coast Guard ship about 85 miles (137 kilometres) north of Alaska's Kiska Island in the Bering Sea came across three Chinese and four Russian naval vessels sailing in single formation.

Ryder, the Pentagon spokesperson, said the recent spike is “something that we'll continue to keep an eye on, but doesn't pose a threat from our perspective.”

Sullivan called for a larger military presence in the Aleutians while advocating for the US to respond with strength to Russian President Vladimir Putin and Chinese President Xi Jinping.

“In the past two years, we've seen joint Russian-Chinese air and naval exercises off our shores and a Chinese spy balloon floating over our communities,” Sullivan said in a statement Tuesday. “These escalating incidents demonstrate the critical role the Arctic plays in great power competition between the US, Russia, and China.”

Sullivan said the US Navy should reopen its shuttered base at Adak, located in the Aleutians. Naval Air Facility Adak was closed in 1997. (AP)

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