President Vladimir Putin warned Washington that a spat between nuclear powers over the Ukraine crisis could threaten global stability and said in remarks published on Wednesday that Russia would not be "blackmailed" by sanctions.
Taking a tough line on the eve of talks with Ukrainian President Petro Poroshenko in Milan, Putin said the sanctions imposed by the United States and the European Union over Moscow's role in the crisis were hindering peace moves.
"We hope that our partners will realize the recklessness of attempts to blackmail Russia, will remember the risks that a spat between major nuclear powers incurs for strategic stability," he told the Serbian newspaper Politika before a brief visit to Belgrade on Thursday.
"For our part, we are ready to develop constructive cooperation on the principles of equality and real consideration of mutual interests."
Putin, who has stepped up anti-Western rhetoric during the crisis, said in August Russia's armed forces, backed by its nuclear arsenal, were ready to meet any aggression and that foreign powers should not "mess with us."
Relations between Moscow and Washington are at a post-Cold War low over Russia's annexation of the Crimean Peninsula and its support for pro-Russian separatists in eastern Ukraine, though Moscow denies sending troops and weapons to back them.
Russia says the West was behind the removal of a pro-Russian president in Ukraine in February and that the takeover of Crimea was justified after it voted overwhelmingly to join Russia.
The sanctions have aggravated Russia's economic problems, with inflation running at an annual rate of almost 8 percent, the rouble falling sharply this year and capital flight topping $75 billion in the first half of 2014.
"Attempts to pressure Russia by means of one-sided, illegitimate restrictive measures are not bringing us towards a resolution, and are complicating dialog," Putin said.
"How can one talk about striving for de-escalation in Ukraine if new sets of sanctions are being introduced almost at the same time as agreements to promote the peace process are reached?"
The European Union introduced new sanctions shortly after a ceasefire deal was reached last month, although it gave Moscow several days to implement the agreement.
The ceasefire has been violated repeatedly and Western powers say the deal agreed at talks involving Russia, Ukraine, the separatists and the Organization for Security and Cooperation in Europe watchdog is not being fully implemented.