WASHINGTON - The United States may arm Ukrainian government forces fighting against Russian-backed rebels, the new US special representative for Ukraine told the BBC.
Kurt Volker said Washington is actively reviewing whether to send weapons to help Ukraine, a move he says could change Moscow's approach.
"Defensive weapons, ones that would allow Ukraine to defend itself, and to take out tanks for example, would actually to help" to stop Russia threatening Ukraine, Mr Volker said in a BBC interview.
He did not think the move would be provocative, saying: "I'm not again predicting where we go on this, that's a matter for further discussion and decision, but I think that argument that it would be provocative to Russia or emboldening of Ukraine is just getting it backwards."
The US State Department last week urged both sides to uphold the ceasefire, agreed in February 2015, in eastern Ukraine.
A former US permanent representative to Nato, Mr Volker was appointed as US special representative earlier this month.
According to the United Nations, more than 10,000 people have died and 1.6 million people displaced since April 2014, when Russia annexed Ukraine's Crimea peninsula.
Meanwhile, the US House of Representatives is expected to vote overwhelmingly on Tuesday (July 25) for a Bill that would slap new sanctions on Russia, Iran and North Korea.
If the Republican-led Senate passes the measure, US President Donald Trump will need to decide whether to sign the Bill or veto it. Rejecting it would carry a risk that his veto could be overridden by lawmakers if they can muster enough support.
The Trump administration has objected to a provision in the sanctions Bill that the president obtain congressional approval before easing any sanctions on Moscow.
"He's going to study that legislation and see what the final product looks like," White House spokesman Sarah Sanders told reporters on Monday when asked whether Mr Trump would support it.
Mr Trump's relationship with Russia has been a focus of the first six months of his presidency as investigations continue into whether his associates colluded with Russian hackers to influence the election on his behalf.
Russia denies interfering in the US election and Mr Trump denies his campaign colluded with Moscow.
As the Republican-controlled House takes up the sanctions Bill, Mr Trump's son-in-law Jared Kushner will visit Capitol Hill for a second straight day to be interviewed about his contacts with Russian officials during the 2016 campaign and the presidential transition.
An earlier version of the Bill, including sanctions on Russia and Iran, passed the Senate 98-2 on June 15. A North Korea sanctions Bill passed the House by 419-1 in May and House lawmakers were becoming increasingly impatient with the Senate's failure to take up that legislation.
House members saw the Iran and Russia sanctions Bill as a chance finally to get the North Korea measure through the Senate.
Reuters contributed to this report.