There can be no negotiations between Washington and Tehran if the United States makes threats against the Islamic republic, the Iranian foreign minister said Wednesday, with President Donald Trump refusing to rule out military action over Iran's crackdown on protesters.

"Conducting diplomacy through military threat cannot be effective or useful. If they want negotiations to take shape, they must certainly set aside threats, excessive demands and raising illogical issues," said Abbas Araghchi after the U.S. deployed an aircraft carrier in the region.

The U.N. Security Council voted Tuesday to terminate a mission that tried to enforce a ceasefire in war-torn Yemen's port city of Hodeida.

"Houthi obstructionism has left the mission without a purpose, and it has to close," said Tammy Bruce of the US delegation, one of 13 on the 15 member council to support ending the mission's mandate.

Russian strikes across Ukraine killed three people and wounded several more, authorities said on Wednesday.

The fresh strikes came hours after Russian attacks on Tuesday night had killed at least 12 people across Ukraine, including five passengers in a train targeted by a drone attack, according to Ukrainian authorities.

Europe must step up efforts on defense and play a bigger role in NATO as U.S. President Donald Trump has "shaken the transatlantic relationship to its foundation", EU top diplomat Kaja Kallas said Wednesday.

"Let me be clear: we want strong transatlantic ties. The US will remain Europe's partner and ally. But Europe needs to adapt to the new realities. Europe is no longer Washington's primary centre of gravity," Kallas told a defence conference in Brussels.

The dollar struggled to bounce back Wednesday following another selloff fuelled by Donald Trump's suggestion he was happy with the currency's recent decline, while tech firms helped most Asian equity markets extend their rally.

Traders are also keeping an eye on the Federal Reserve's latest meeting, hoping for some guidance on its plans for interest rates amid uncertainty over the US president's policies following his latest tariff threats.

Saudi Crown Prince Mohammed bin Salman told Iranian President Masoud Pezeshkian during a call on Tuesday that the Gulf monarchy would not allow attacks on Iran to be launched from its soil.

Prince Mohammed "affirmed during the call the kingdom's position on respecting the sovereignty of the Islamic Republic of Iran, and that the Kingdom will not allow its airspace or its territory to be used for any military actions against" Iran, Saudi Arabia's foreign ministry said in a statement.

Recent clashes between Syria's military and Kurdish forces are a "setback" and a "plot" to derail the PKK peace process with Turkey, a spokesman for the Kurdish militant group told AFP on Tuesday.

"The developments in Syria and the larger Middle East have a direct effect on the peace process in Turkey," said Zagros Hiwa, spokesman for the political wing of the Kurdistan Workers' Party.

More than half a million Americans woke up without power Tuesday, as freezing temperatures gripped swathes of the country in a monster storm that has killed at least 30 people.

A frigid, life-threatening Arctic air mass could delay recovery as municipalities from New Mexico to Maine tried to dig out following the storm, which dropped a vicious cocktail of heavy snow and wind, along with freezing rain and sleet.

A U.S. naval strike force led by an aircraft carrier was in Middle Eastern waters on Tuesday as Iran vowed to hit back against any strike and President Donald Trump said he believed the Islamic republic still wanted talks.

Washington has not ruled out new military intervention against Tehran over its crackdown on protests, which according to rights groups saw thousands of people killed within days.

China promised on Tuesday to provide Cuba with "support and assistance" in the face of repeated threats from the United State, which weeks ago removed Havana's ally in Venezuela Nicolas Maduro.

Beijing and Havana are longtime socialist allies, and Chinese authorities have consistently opposed the economic blockade imposed on the island for decades by the United States.