ROME - US Secretary of State John Kerry is scheduled to hold a ministerial-level international conference?in Rome?on Thursday on offering more support to the Syrian opposition.

The move was widely considered as the centerpiece of the US top diplomat's first overseas mission since taking office.

The meeting, organized by Italy's foreign ministry upon Kerry's request, will be attended by delegations from a dozen of countries most involved in managing the Syrian crisis, including the Syrian opposition, according to a statement from Italy's foreign ministry.

The Syrian opposition was persuaded by Kerry to attend the meeting, before which it had threatened to boycott the conference as a protest against the little help it said it had obtained from the West.

In the middle of an 11-day tour of Europe and the Middle East, Kerry arrived in Rome on Wednesday after having talks with officials in London, Berlin and Paris. He said in London that he was not coming to Rome "simply to talk" but to "make a decision about next steps".

The US government has declared its latest intention to push for Syrian President Bashar al-Assad's resignation and a political transition to end the almost two-year-long conflict in Syria.

While efforts are reportedly underway to generate dialogues between Assad's regime and the opposition on the diplomatic front, a deadly explosion and fighting earlier this week in Syria's capital Damascus apparently escalated the crisis.

Kerry said the Obama administration had been considering new steps to further support the Syrian opposition and speed up the departure of President Assad.

The European Union also agreed to a British proposal of sending non-lethal assistance to armed groups inside Syria, but European nations have come to no decision yet on what sort of aid to be sent.