The lawmakers spoke on March 24, a day after the U.S. House of Representatives approved a resolution urging President Barack Obama to provide Ukraine with lethal weapons to defend itself against Russian "aggression."
A Just Russia party lawmaker Mikhail Yemelyanov told the State Duma, the lower parliament house, that if the "the United States actually starts to deliver lethal weapons to Ukraine we should openly back militias...with weapons, and reinstate the president's right to send troops to Ukrainian territory."
He was referring to Russian-backed separatists whose war with government forces has killed more than 6,000 people in eastern Ukraine since April 2014.
Frants Klintsevich, a ruling United Russia party lawmaker, said U.S. supplies of lethal weapons would "in a second" destroy the fragile cease-fire deal now in place.
Parliament gave Putin the formal authority to send troops to Ukraine in March 2014 , a move that sent a warning signal to the West following the ouster of Ukrainian President Viktor Yanukovych.
The authority was later withdrawn, and Russia denies sending troops into eastern Ukraine despite what Kiev and NATO say is overwhelming evidence.
Source: Radio Free Europe