Iran has denied that its missile the Ukrainian aircraft that crashed near Tehran with 176 passengers on board on Wednesday had been hit by a missile, Reuters reported on Friday, quoting the state media.

“All these reports are a psychological warfare against Iran,” Iranian government spokesperson Ali Rabiei said in a statement. “All those countries whose citizens were aboard the plane can send representatives and we urge Boeing to send its representative to join the process of investigating the black box.”

The US National Transportation Safety Board has said that it will join the investigation into the crash of the Ukrainian airliner, reported AFP. The agency said it had “received formal notification” from Iran of the crash.

“The NTSB has designated an accredited representative to the investigation of the crash,” said the agency that investigates transport accidents. “The NTSB continues to monitor the situation surrounding the crash and evaluate its level of participation in the investigation. As with any investigation in which the NTSB is involved, the agency will not speculate about the cause of the crash.”

Iran’s denial of being involved in the crash came after leaders of three countries claimed they had received intelligence that the Ukrainian aircraft was shot down by an Iranian surface-to-air missile, albeit mistakenly. Canadian Prime Minister Justin Trudeau, United Kingdom’s Boris Johnson and Australia’s Scott Morrison claimed they had received information of Iran’s involvement in the plane crash.

“We have intelligence from multiple sources including our allies and our own intelligence,” said Trudeau. “The evidence indicates that the plane was shot down by an Iranian surface-to-air missile.”

There were 82 Iranians and 63 Canadians on the plane, with nine of the 176 people on board being crew members, officials said.

Johnson said he had received inputs about the flight being shot down by a missile attack from Iran, The Telegraph reported. However, he added: “This may well have been unintentional.”

Australian Prime Minister Morrison on Friday made a similar comment about the intelligence, but added there was “nothing to suggest now at this point an intentional act”, The Sydney Morning Herald reported. He also called for an investigation into the matter “that would include undertaking all efforts to ensure we get recovery of the black box recorder that can obviously inform that investigation.”

United States President Donald Trump also hinted at Iran’s involvement behind the tragedy and said that the aircraft was flying over a “pretty rough neighbourhood”, suggesting that the flight may have been shot down by “mistake”. He also rejected Iran’s earlier claim that a mechanical problem brought down the aircraft.

Three government officials of the United States told Reuters that evidence suggested Iran shot down the Ukrainian airline accidentally. One of the officials cited a thorough review of satellite data, and said that Iran had allegedly tracked the plane on its radar before shooting the missiles.

Another official claimed that two minutes after Boeing 737-800 took off heat signatures from a surface-to-air missile was detected. However, Iran’s civil aviation official Hasan Rezaeifa told state-run media that it was “impossible that a missile hit the Ukrainian plane.”

In a Facebook post on Thursday, secretary of Ukraine’s security and defence council Oleksiy Danylov had listed three possible causes for the crash. One was a mid-air clash with a drone or another flying object, engine destruction or an explosion due to technical causes, and an explosion inside the plane due to a terror attack.

US House votes to limit Trump’s powers to make war on Iran

The US House of Representatives on Thursday adopted a symbolic resolution seeking to limit President Donald Trump’s ability to declare war on Iran, reported BBC. It aims to mandate approval from the Congress before any conflict with Iran, except in cases of an imminent attack against the US.

The resolution was passed 224-194. Three Republican Party members also voted in favour of the resolution. However, it needs to be ratified by the Senate, which is dominated by Republicans.

House Speaker Nancy Pelosi said Trump “must de-escalate and must prevent further violence”. She added: “America and the world cannot afford war.”

Trump, meanwhile, claimed he does not need any approval to launch attacks, reported AFP. “I don’t have to,” said the president when asked if he would seek congressional approval for more military action against Iran. “And you shouldn’t have to. Because you have to make split-second decisions sometimes.”

Renewed tensions between the United States and Iran reached a peak after Tehran shot over a dozen ballistic missiles at two airbases housing United States troops in Iraq on Wednesday. The attack was in retaliation for the assassination of Iranian General Qassem Soleimani, said Iran’s Revolutionary Guard. On January 3, an airstrike by the US at Baghdad’s airport killed Iranian Major-General Qassem Soleimani, head of the elite Quds Force, and Abu Mahdi al-Muhandis, the deputy commander of Iran-backed militias known as the Popular Mobilization Forces.

Iran will never have a nuclear weapon, claims Trump

US President Donald Trump on Thursday said Iran will never have a nuclear weapon, adding that Tehran was getting “hurt very badly” by American sanctions, reported AFP. New sanctions were imposed on Iran after it launched an attack on two airbases housing United States soldiers in Iraq in retaliation for its top military commander Qassem Soleimani’s assassination.

“Iran right now is a mess,” he told reporters. “They can straighten out the economics of their country very, very quickly. Let us see whether or not they negotiate.”

Trump claimed that Iran will never possess a nuclear weapon. “They understand that,” he added. “We have told them very strongly. Iran now is not wealthy like it was when President (Barack) Obama handed USD 150 billion. There are much different country.”

On Sunday, Tehran said it had decided to no longer respect any limits on its nuclear activities set by the 2015 deal.

The US, under former President Barack Obama, was among six countries that had signed the nuclear deal with Iran in 2015, putting limits on Tehran’s nuclear activities in exchange for lifting of crippling sanctions. The limits were defined in terms of the purity level of uranium enrichment and the stock of enriched uranium.

Trump has urged countries to end the 2015 nuclear deal with Iran that his administration walked out of in 2018. On Thursday, the president said the Iranian nuclear deal has not worked. “I always call it the Iran Nuclear Deal that didn’t work,” he added. “The Iran Deal. It was just something that it is no good for our country. It expires in a short time.”