<div><span style="font-size: 1rem;">The United States would respond decisively to any Russian use of nuclear weapons against Ukraine and has spelled out to Moscow the “catastrophic consequences” it would face, US National Security Adviser Jake Sullivan has said.</span><br></div><div><br></div><div>“If Russia crosses this line, there will be catastrophic consequences for Russia. The United States will respond decisively,” Sullivan told NBC’s “Meet the Press” program.</div><div><br></div><div>Sullivan did not describe the nature of the planned US response in his comments on Sunday but said the United States has privately to Moscow “spelled out in greater detail exactly what that would mean,” reports Al Jazeera</div><div><br></div><div>He said that the United States has been in frequent, direct contact with Russia, including during the last few days to discuss the situation in Ukraine and Putin’s actions and threats.&nbsp;</div><div><br></div><div>bnbd24/fas</div>