DUBAI (Reuters) - Iran will decide on Sunday about its next step to further roll back its commitments to a 2015 nuclear deal with major powers, Iranian Foreign Ministry spokesman was quoted as saying, days after the U.S. killing of top Iranian military commander Qassem Soleimani.

President Donald Trump pulled the United States out of the 2015 agreement between Tehran and six major powers in 2018 and reimpoised sanctions on Iran that have crippled its economy. Hostilities between the countries escalated sharply after Friday's U.S. drone attack in Baghdad that killed Soleimani.

"Tonight, there will be a very important meeting to decide about our next nuclear step and the implementation of the deal ... considering the recent threats (by America) it should be underlined that in politics, all developments and threats are linked to each other," spokesman Abbas Mousavi was quoted as saying by state news agency IRNA.

In reaction to the U.S. policy of "maximum pressure" since Trump pulled out of the nuclear agreement, Iran has gradually distanced itself from the deal, under which Tehran undertook to curb its nuclear activity in exchange for a lifting of many international sanctions.

Iran has warned that it will further decrease its commitments if European parties to the agreement fail to shield Tehran's economy from U.S. penalties.

In November, Iran gave Britain, France and Germany a third 60-day deadline to salvage the deal or face a further decrease of Iran's commitments to nuclear pact.

(Writing by Parisa Hafezi; Editing by Frances Kerry)