Unidentified assailants opened fire on a polio vaccination team in northwestern Pakistan on Wednesday, killing one of those handing out doses and one policeman escorting him, police said.

The attack in the region bordering Afghanistan comes two days after Pakistan launched its latest national campaign to stamp out the virus, which still poses a health threat in the South Asian nation, although mostly eradicated elsewhere, Reuters reported.

"Unidentified armed men opened fire on polio vaccination team in a subdivision of Bajaur tribal district as they were on the vaccination campaign," district police officer Waqas Rafique told Reuters.

No group has claimed responsibility, but previously Islamist militant groups in the region have claimed similar attacks on polio teams, falsely portraying the inoculation campaigns as a Western conspiracy to sterilise children.

Pakistan began its latest national campaign earlier this week, aiming to administer the vaccine to up to 30 million children, the prime minister's office said.

Pakistan and Afghanistan are the only two countries in the world still struggling to eradicate polio, read the report.

A local police union group called for a strike by policemen and a boycott of security duties for the vaccination campaign in the Bajaur district following the killing of their colleague.

Reports of Iranian weapons transfers to Russia are "ugly propaganda" to conceal Western military support to Israel, Iran's foreign ministry said on Tuesday, after Western powers said they would impose new sanctions on Tehran over the issue, Reuters reported.

"The publication of false and misleading reports about the transfer of Iranian weapons to some countries is simply an ugly propaganda to conceal the large illegal arms support of the United States and some Western countries for the genocide in Gaza," foreign ministry spokesperson Nasser Kanaani said in a post on X, without mentioning the new sanctions.

U.S. Secretary of State Antony Blinken said on Tuesday that Russia had received ballistic missiles from Iran and would likely use them in Ukraine within weeks, warning that cooperation between Moscow and Tehran threatened wider European security.

Alongside the United States, Britain, Germany and France said they would apply new sanctions on Iran, including measures against its national airline Iran Air, read the report.

London, Berlin and Paris also announced the cancellation of bilateral air services agreements with Tehran.

"This action by the three European countries is the continuation of the West's hostile policy and economic terrorism against the people of Iran, and it will face a proportionate response by Iran," Kanaani said in a later statement published on the foreign ministry's Telegram page.

Iran is already one of the most heavily sanctioned countries in the world, and some experts have questioned the impact of more economic penalties that might hurt the middle classes more than the country's leaders, Reuters reported.

Any Iranian transfer of ballistic missiles to Russia would mark a sharp escalation in the Ukraine war, the United States said on Friday, following reports that the two countries had deepened ties in recent weeks with such an arms transfer, Reuters reported.

Reuters reported in August that Russia was expecting the imminent delivery of hundreds of Fath-360 close-range ballistic missiles from Iran and that dozens of Russian military personnel were being trained in Iran on the satellite-guided weapons for eventual use in the war in Ukraine.

Short-range missiles have now been delivered to Russia by Iran, the Wall Street Journal reported on Friday, citing an unnamed U.S. official.

"We have been warning of the deepening security partnership between Russia and Iran since the outset of Russia's full-scale invasion of Ukraine and are alarmed by these reports," said White House National Security Council spokesperson Sean Savett.

"Any transfer of Iranian ballistic missiles to Russia would represent a dramatic escalation in Iran's support for Russia's war of aggression against Ukraine."

Another U.S. official told Reuters they were watching the potential Iranian-Russian missile transfers closely.

The potential moves come after the United States and partners, including in Europe, warned that such a step by Iran could meet with consequences. The Western countries have been watching Iran and Russia's deepening ties in recent months with increasing concern.

Iran's mission to the United Nations in New York said on Friday that Tehran's position on the Ukraine conflict was unchanged.

"Iran considers the provision of military assistance to the parties engaged in the conflict - which leads to increased human casualties, destruction of infrastructure, and a distancing from ceasefire negotiations - to be inhumane," it said.

"Thus, not only does Iran abstain from engaging in such actions itself, but it also calls upon other countries to cease the supply of weapons to the sides involved in the conflict," the mission said.