With relations between Washington and Moscow deteriorating, Russian news agencies are quoting a top defense official as saying the possibility of reopening Russian military facilities in Cuba and Vietnam is under consideration.

Asked Friday by lawmakers in the State Duma, the lower house of Russia's parliament, if the Russian military might return to countries like Cuba and Vietnam, Deputy Defense Minister Nikolai Pankov replied: "We are doing this work." He provided no details.

The Soviet Union established a Signals Intelligence (SIGINT) base in Lourdes, Cuba, in the early 1960s and a naval base in Cam Ranh Bay, Vietnam, in the late 1970s. While Russia continued to operate those facilities following the breakup of the Soviet Union in 1991, they were shut down in 2001 and 2002, respectively.

Russia is currently operating an air base and a naval base in Syria.

According to Russian news agencies, Kremlin spokesman Dmitry Peskov was also asked Friday about the possibility of reestablishing bases in Cuba and Vietnam. He refused to comment on it directly, saying the question should be addressed to the defense ministry.

However, Peskov was quoted as saying: "The international situation is not static; it is rather fluid. You can see that the last two years have introduced in general significant adjustments to international affairs and the international security regime. So, naturally, all countries in accordance with their national interests are assessing these changes and taking certain measures in the direction that they see fit."

In July 2014, President Vladimir Putin denied media reports that Russia was planning to reopen the Lourdes Signals Intelligence base in Cuba.

The comments about reestablishing Russian military facilities far from home came as tensions between Russia and the United States grew.

On Monday, Washington suspended talks with Moscow on a cease-fire in Syria, citing continued military attacks against civilian targets there. That same day, President Vladimir Putin suspended an agreement with the U.S. on disposing weapons-grade plutonium, citing "unfriendly actions" by Washington — a reference to sanctions on Moscow for its actions in Ukraine.

On Wednesday, Russia suspended an agreement with the United States on cooperation on nuclear and energy-related research.