Russia will exit the Intermediate-range Nuclear Forces (INF) treaty in six months as part of a symmetrical response to the United States' pullout, the Interfax news agency cited Foreign Minister Sergei Lavrov as saying.

Lavrov's statements came yesterday after Russia's defense ministry's announcement over developing land-based intermediate range missiles within two years. Russia has rejected the U.S. claim that it has built and deployed a cruise missile that violated the treaty's ban on land-based cruise and ballistic missiles with a range of 500 to 5,500 kilometers.

But Russian Defense Minister Sergei Shoigu said Tuesday such weapons need to be designed now, charging that the U.S. has already started developing such weapons. He said at a meeting with senior officers that a land-based version of the navy's Kalibr cruise missile and a new land-based hypersonic missile must be built in 2019-20.

President Vladimir Putin said at the weekend that Russia had suspended the Cold War-era pact after Washington announced it would withdraw in six months unless Moscow ends what it says are violations of the 1987 pact.

During his annual State of the Union address, U.S. President Donald Trump vowed Tuesday that the United States would outspend Russia on missiles without a fresh international accord after he ditched a landmark Cold War treaty.

The U.S. last week started the process of exiting INF treaty, saying that Russia has been violating the pact through a new missile system and ignored repeated complaints.

"Under my administration, we will never apologize for advancing America's interests," Trump told U.S. lawmakers assembled in the House chamber. "Perhaps we can negotiate a different agreement, adding China and others. Or perhaps we can't, in which case, we will outspend and out-innovate all others by far."

While pointing the finger at Russia, U.S. officials have voiced concern that the 1987 treaty does not constrain China, whose rapidly growing military relies on medium-range missiles as a core part of its defense strategy. The INF treaty banned all missiles with a range of 500 to 5,500 kilometers, a legacy of the end of the Cold War as last Soviet leader Mikhail Gorbachev and U.S. president Ronald Reagan sought to ease European fears of an arms race that would destroy their cities.