EU foreign ministers have condemned "atrocities and abuses" against religious minorities in Iraq, with Germany warning it cannot stand by and watch people being "slaughtered".
The emergency meeting in Brussels left it to individual states whether they would arm Iraq's Kurds against Islamic State (IS) militants in the north.
France and the US have already moved to supply the Kurds with arms.
IS violence has driven an estimated 1.2 million Iraqis from their homes.
After the talks, German Foreign Minister Frank-Walter Steinmeier said he was flying to Iraq to meet Kurdish leaders and the government in Baghdad to discuss what support is most needed.
"We cannot just watch as people are slaughtered there," he said after the foreign ministers' meeting in Brussels. "If the current threat level persists, I can't rule out that we will have to deliver weapons."
Iraq has appointed a new prime minister to tackle the crisis. Haider al-Abadi, deputy speaker of the parliament, took over from his fellow Shia Muslim politician Nouri Maliki on Thursday, ending a dangerous political deadlock in Baghdad.
One of Iraq's most powerful Sunni tribal leaders, Ali Hatem Suleiman, has reportedly said he is ready to work with the new prime minister if he protects the rights of Sunnis.
Grand Ayatollah Ali al-Sistani, Iraq's most influential Shia cleric, has already thrown his weight behind the new prime minister in Baghdad.
In another development, there are reports of fierce fighting with IS militants in the predominantly Sunni region of Anbar, west of Baghdad.
AFP news agency quoted a Sunni tribal leader, Sheikh Abduljabbar Abu Risha, as saying an "uprising" was under way against IS, while Anbar police chief Maj-Gen Ahmed Saddak said security forces were backing the fight to drive out IS.
'Atrocities and abuses'
After meeting in Brussels, the EU foreign ministers said in a statement: "The EU remains seriously concerned about the deterioration of the security situation in Iraq, and condemns in the strongest terms the attacks perpetrated by [IS] and other associated armed groups.
"The EU also condemns the atrocities and abuses of basic human rights, in particular when committed against targeted religious minorities and most vulnerable groups."
The ministers called for investigations into possible crimes against humanity.
They welcomed the "decision by individual Member States to respond positively to the call by the Kurdish regional authorities to provide urgently military material.
"Such responses will be done according to the capabilities and national laws of the Member States, and with the consent of the Iraqi national authorities."
The emergency EU meeting was called by France, whose foreign minister, Laurent Fabius, had criticised the EU for inaction on Iraq.
Military aid pledges
- The US and France have already started arming Kurdish fighters
- The UK says it would "favourably consider" any request for arms from the Kurds
- The Czech Republic says it is working on the "preparation of military supplies" to the Kurds
- The Netherlands said on Thursday that it would also consider helping arm both Kurdish and Iraqi government troops
Several EU countries, as well as the US, have made drops of aid in northern Iraq in the past week.
The US has also engaged in limited air strikes against IS targets.
The governor of Dohuk province in northern Iraq, Farhad Atrushi, has said the US and UK are politically and ethically responsible for helping Iraq.
Warning of the threat of "genocide", he told the BBC: "We have hundreds of thousands [of refugees]. We're going to face an international humanitarian catastrophe because many of these kids and children will die."
He said that Kurdish authorities needed at least two months and hundreds of millions of dollars to be able to provide shelter for Iraqi refugees.
'Refugees are everywhere': Iraqi Christian cleric in Irbil
I lived all my life in Iraq. I have never seen this evil before. Christians were forced to leave Mosul. They were given three options - convert to Islam, pay tax or be killed.
I have one family in my church. IS took everything from them. They took their money, they took even their gold rings, clothes and they even took the medicine of an old lady who was them.
Refugees are everywhere. They are in churches. They are in public schools. They are in streets. They are in parks. Now you can find 40 people living in one house. Many people have come to me and said we are seven families in one house.
The cleric spoke to BBC Radio 5 Live on condition on anonymity
Mr Maliki's resignation on Thursday evening was welcomed by the UN and US.
The resignation brought an end to eight years of often divisive rule, when Mr Maliki's government was accused of favouring the Shia Muslim majority.
Mr Abadi is one of Iraq's most senior politicians, having held several high-profile posts since returning from exile in 2003.
He is regarded by some as a moderate within Mr Maliki's Dawa party, and has shown more of a willingness to compromise than his predecessor.
In a Facebook post, Mr Abadi urged Iraqis to unite in the face of "strong and dangerous challenges". He said he would be prepared to give up his life in defence of the nation.
The change in government comes as the Iraqi army proved unable to stop Islamist fighters from seizing vast areas in northern Iraq.
A UN Security Council meeting on Friday is expected to approve a resolution threatening sanctions against any country which finances or supports IS.