REUTERS AND AP - Russia test-fired a Sineva intercontinental missile from a submerged submarine in the Barents Sea on Wednesday as part of a check on the reliability of the navy's strategic forces, the Defense Ministry said.

The liquid-fueled missile, which can carry nuclear warheads, was fired from the Tula submarine to the Kura Test Range in the far eastern region of Kamchatka, RIA news agency quoted the ministry as saying. It gave no other details.

The Sineva, which has a range of about 12,000 km (7,500 miles), entered service in 2007 and is part of efforts to prevent the weakening of Russia's nuclear deterrent.

President Vladimir Putin has underlined the importance of the nuclear deterrent during the standoff with the West over the crisis in Ukraine, and Russia has held several military exercises during the crisis that have alarmed Western powers.

Russia informed the United States on Tuesday that it will boycott the 2016 Nuclear Security Summit, diplomats told The Associated Press on Tuesday, potentially stripping the meeting of one of its key participants and hurting efforts initiated by President Barack Obama to reduce the threat of nuclear terrorism.

Officials already had told the AP on Monday that Moscow was absent from last week's initial summit planning session in Washington but had left it unclear whether Russia planned to attend the summit itself.