The U.S. formally left the Intermediate Nuclear Forces (INF) treaty with Russia on Friday after determining that Moscow was violating the treaty and had already deployed at least one banned type of missile, an accusation the Kremlin denies.

The pact banned land-based missiles with a range of between 310 miles and 3,400 miles (500-5,500 km), reducing the ability of both countries to launch a nuclear strike on short notice.

Putin on Monday, according to (Reuters/NAN) report, held a meeting with his Security Council after which he ordered the defence and foreign ministries and Russia’s SVR foreign intelligence service to closely monitor any steps the U.S. took to develop, produce or deploy missiles banned under the defunct treaty.

“If Russia obtains reliable information that the U.S. has finished developing these systems and started to produce them Russia will have no option other than to engage in a full-scale effort to develop similar missiles,” Putin said in a statement.

In the meantime, he said Russia’s arsenal of air and sea-launched missiles combined with its work on developing hypersonic missiles meant it was well placed to offset any threat emanating from the U.S.

It was now essential, he added, for Moscow and Washington to resume arms control talks to prevent what he described as an “unfettered” arms race breaking out.

“In order to avoid chaos with no rules, restrictions or laws, we need to once more weigh up all the dangerous consequences and launch a serious and meaningful dialogue free from any ambiguity,” Putin said.