US senators on Sunday touted a bipartisan bill that would arm US President Donald Trump with “sledgehammer” sanctions to use against Russia, ahead of a visit by the US special envoy to Ukraine.

Trump has indicated he would be open to the sanctions bill as relations with Russian counterpart Vladimir Putin grow increasingly frosty.

US special envoy Keith Kellogg is expected to begin his latest visit to Ukraine while Trump said he would make a “major statement … on Russia” on Monday.

Republican Senator Lindsey Graham said he had majority backing in the Senate for his bill, which was gaining momentum as Washington-led peace efforts in Ukraine have struggled to make headway.The bill would allow Trump “to go after Putin’s economy, and all those countries who prop up the Putin war machine”, Graham told broadcaster CBS news.

Trump, who has repeatedly said he is “disappointed” with Putin as Moscow unleashed deadly barrages of missiles against Kyiv, has hinted he might finally be ready to toughen sanctions.