US Secretary of State Mike Pompeo on Friday promised Ukraine to fight the planned Nord Stream 2 gas pipeline from Russia to Germany, saying the project undermined European security.
Pompeo said Ukraine had "no greater friend than the United States" in its struggle against "Russian aggression" as he met the embattled country's foreign minister, Pavlo Klimkin, in Washington.
"We'll keep working together to stop the Nord Stream II project that undermines Ukraine's economic and strategic security and risks further compromising the sovereignty of European nations that depend on Russian gas," Pompeo told reporters as he stood next to Klimkin.
"We do not want our European friends to fall prey to the kind of political and economic manipulation Russia has attempted in Ukraine since it cast off its Soviet shackles," Pompeo said.
The pipeline, which has also been criticized by Poland and other former Soviet bloc countries, aims to double the capacity of the existing Nord Stream I pipeline by the end of 2019 -- further allowing Russia to bypass Ukraine, its traditional route to supply Europe.
Germany, backed by France and Austria, has billed the project led by Russia's Gazprom as a way to ensure stable and lower-cost energy.
US lawmakers led by the late senator John McCain passed legislation opening the path to sanctions against investors in the pipeline, although the ultimate decision lies with President Donald Trump.
The US leader has sent mixed signals, berating Germany as "totally dependent" on Moscow for energy but also warming to President Vladimir Putin.
Trump caused consternation at a July summit in Helsinki where he appeared to accept Putin's denials of interference in the 2016 US election and, ahead of the meeting, sounded open to recognizing Moscow's 2014 annexation of Crimea.
Pompeo reiterated his post-summit statement of US opposition to the takeover of Crimea, a Black Sea peninsula of Ukraine whose population is largely ethnically Russian.
"The United States will never accept Russia's attempted annexation of Crimea," Pompeo said.
"We will continue to impose consequences until Moscow fully implements the Minsk agreements and returns control of Crimea to Ukraine," he said, a week after the United States slapped sanctions on Russians over business dealings on the peninsula.
The 2015 Minsk summit laid out a ceasefire and international monitoring in eastern Ukraine. But a pro-Russian insurgency has persisted, with a death toll that has crossed 10,000.