Pompeo to hold talks on Iran in Brussels en route to Russia

US Secretary of State Mike Pompeo will cancel the Moscow leg of his Russia trip, but will meet President Vladimir Putin and Foreign Minister Sergei Lavrov in the Black Sea resort of Sochi as planned on Tuesday, a State Department official said.

Pompeo, who departed from Joint Base Andrews near Washington en route for Brussels, will hold talks with European officials on Iran and other issues on Monday before heading to Russia, the official added, speaking on condition of anonymity.

On Sunday, a senior Iranian Revolutionary Guards commander said the US military presence in the Gulf used to be a serious threat but now represented a target, the Iranian Students' News Agency (ISNA) said.

Forces sent by the US military to the Middle East include an aircraft carrier and B-52 bombers, in a move US officials said was aimed at countering "clear indications" of threats from Iran to American forces in the region.

US President Donald Trump also has stepped up economic pressure on Iran, moving to cut off all its oil exports, to try to get Tehran to curb its nuclear and missile programs as well as end support for proxies in Syria, Iraq, Lebanon and Yemen.

Speaking to CNBC in an interview to be broadcast on Monday, Pompeo said the US deployments were in response to intelligence about potential Iranian attacks and aimed both to deter them and to be able to respond if necessary.

"In the event that Iran decided to come after an American interest - whether that be in Iraq or Afghanistan or Yemen or any place in the Middle East - we are prepared to respond in an appropriate way," he said, adding "Our aim is not war."

Last week, European countries said they wanted to preserve Iran's nuclear deal and rejected "ultimatums" from Tehran, after Iran eased curbs on its nuclear programme and threatened moves that might breach the 2015 international pact.

Iran's announcement on Wednesday, related to curbs on its stockpiling of nuclear materials, was in response to US sanctions imposed following Trump's withdrawal of the United States from the accord with Tehran a year ago.

On his first trip to Russia as US secretary of state, Pompeo is expected to discuss with Putin and Lavrov the "aggressive and destabilising actions" Moscow has taken around the world, a senior state department official said last week.

Pompeo would reiterate US concerns about Russia's role in Venezuela and Syria and its breach of the Intermediate-range Nuclear Forces (INF) Treaty, as well as Russian attempts to meddle in US elections, the official told reporters in a preview of his trip.

Trump spoke with Putin by telephone on May 3, and said they discussed the possibility of a new accord limiting nuclear arms that could eventually include China in what would be a major deal between the globe's top three atomic powers.

The 2011 New START treaty, the only US-Russia arms control pact limiting deployed strategic nuclear weapons, expires in February 2021 but can be extended for five years if both sides agree.

Without the pact, it could be harder to gauge each other's intentions, arms control advocates say.

Trump has called the New START treaty concluded by his predecessor, Barack Obama, a "bad deal" and "one-sided".

Pompeo had been due to meet US embassy staff and members of the business community in Moscow on Monday before heading to Sochi.