US President Donald Trump signed a bill on Friday authorizing new sanctions designed to pressure Russia over its war in Ukraine, after Congress gave its approval after months of delay.

Washington is pushing to revive a mediated path towards ending the conflict as Moscow intensifies attacks against Ukraine, even though much of its attention -- and munitions -- are focused on the ongoing war against Iran.

The legislation, which US lawmakers approved this week, takes aim at Russia's energy and defense sectors, alongside President Vladimir Putin and other senior officials.

It also targets Moscow's so-called shadow fleet of tankers used to evade Western sanctions, and allows Trump the authority to impose tariffs of up to 100 percent on major buyers of Russian oil and gas.

That could potentially cover China and India, and furthers efforts to cut off revenue financing Moscow's war.

The Republican-led Ho...