Kurdish opposition armed groups have already come under Iranian fire since the war began with US and Israeli strikes on Iran over the weekend.

Still, and despite Washington's record of abandoning the Kurds in the region, they pin their hopes on the war to weaken the Islamic republic and may even go so far as to ally with the United States.

On Thursday, US President Donald Trump told news agency Reuters he would "be all for" an offensive by Iranian Kurdish fighters into Iran, but declined to say if Washington would provide them with air cover.

- What is happening in northern Iraq? -

Iraq's autonomous Kurdistan region hosts camps and rear bases operated by several Iranian Kurdish rebel groups that have repeatedly faced cross-border strikes from Iran, which accuses them of serving Western or Israeli interests.

In recent days, Iranian forces have struck positions belonging to these groups, which have formed an alliance to seek the overthrow of the Islamic republic and ultimately secure Kurdish self-determination.

An Iraqi security official told AFP that Iranian officials have warned Iraq that hundreds of armed Kurdish fighters may try to infiltrate Iran.

So far, no forces have entered Iran, several sources from the opposition groups told AFP.

But it is not an unlikely scenario.

Kalel Kani Sanani, a spokesperson for the Kurdistan Freedom Party PAK, told AFP that were the strikes on Iran to continue, "the regime forces will be weakened" and conditions will become ripe for a "popular uprising".

"The armed groups will then be able to confront what remains of the Iranian regime's forces."

Sanani said preparations have already been made.

"We are closely monitoring the course of the war, and if it continues like this, we are likely to witness an uprising in Iranian Kurdistan."

- What do Kurds want? -

Sanani said "we believe that this war will create an opportunity for the people of Kurdistan to live freely".

The Kurds, an ethnic minority with a distinct culture and language, are rooted in the mountainous region spread across Turkey, Syria, Iraq and Iran.

They have long fought for their own homeland, but for decades suffered defeats on the battlefield and massacres in their hometowns.

They make up one of Iran's most important non-Persian ethnic minority groups.

The 1991 Gulf War, which began after Iraq invaded Kuwait, paved the way for the Kurds' de facto autonomy in northern Iraq.

Back then, the US and its allies had set up a no-fly zone to shield the Kurds from Saddam Hussein's forces.

"Iranian Kurds want to follow the path" of their Iraqi fellows, said Adel Bakawan, director of the European Institute for Studies on the Middle East and North Africa.

They appeared ready to receive help from the US.

"They are pragmatic," Bakawan said, adding that the Kurds were well aware that Iran's future was not being shaped in Iran but in the US and Israel.

- Why trust the US? -

Sanani said "if they help us overthrow or weaken the regime in Iranian Kurdistan and protect us as they did in Iraqi Kurdistan in 1991, we will accept" their aid.

Renad Mansour from the Chatham House think tank said this "appears to be another chapter in a long history in which the US seeks different Kurdish militant groups... to support in various battles".

Having long backed Syria's Kurds, the US recently declared their joint mission to fight jihadists over and then allowed the new Islamist government's forces to advance against them.

Still, Iran's Kurds see an alliance with the US as "a historic opportunity", Mansour said.

They may later feel its impact, but for now, what we might see is "just another marriage of convenience".

- What about Iraq, Syria, Turkey? -

Baghdad has said it was determined to uphold its security agreement with ally Tehran to protect their shared border, and Kurdish authorities have denied involvement in plans to arm or send Kurdish opposition forces to Iran.

Much is at stake for Iraq's Kurdistan, which has already been pulled into the regional war and is facing drone and missile attacks on US bases stationed there.

Turkey, which has battled its own Kurdish insurgency for decades, warned of activities that would "negatively affect... the overall peace and stability of the region".

Bakawan, however, said Iran's Kurds should not see Turkey as an enemy and instead follow the model of Iraq's Kurdistan, which counts Ankara as its strongest ally.

Mansour said that Syria, despite its strained relations with the Kurds, would welcome any effort to bring down the Islamic republic, which it considers an enemy.