U.S. President Donald Trump's decision to ramp up arms shipments to Ukraine is a signal to Kyiv to abandon peace efforts, Russia said on Thursday, vowing it would not accept the "blackmail" of Washington's new sanctions ultimatum.

Senate Majority Leader John Thune says Republicans will vote on a Russia sanctions bill once Trump approves it, as pressure mounts on Moscow to negotiate peace in Ukraine.

As Russia defies calls for a ceasefire in its war with Ukraine, members of Congress are moving to slap the country with new sanctions. The effort effort is a rare bipartisan issue in Congress.

To appreciate the dramatic shift in President Donald Trump’s policy towards Ukraine, consider two scenes in the Oval Office, months apart:

In a major shift toward Ukraine, Trump announces a plan to send weapons, including Patriot systems, and threatens 100 percent tariffs if Russia doesn’t reach a deal soon.

Trump ripped into the Russian leader, accusing him of being “all talk” after months of U.S. efforts to broker a deal to end the war he started by ordering an invasion of Ukraine, and said he’d prefer not to use the powerful secondary sanctions he’s threatened but stressed that the war “has got to stop.”