Support for equal partnership entitlements for same-sex couples in the US continues to rise, according to a new poll by Reuters.

It comes as the US Supreme Court prepares to decide whether the federal government may deny benefits to same-sex married couples that it allows for heterosexual couples.

According to Reuters/Ipsos polling of 2,886 Americans, 55% of those surveyed said married same-sex couples should be able to qualify for social security survivor payments and other benefits provided to married heterosexual couples.

A more extensive Reuters/Ipsos poll of 24,455 people between 1 Jan and 14 March found only a quarter of Americans opposed same-sex marriages or civil unions.

The greatest support was in the north-east region of the US, with 69% of adults supporting same-sex marriages or civil unions. However, support fell to 57% in the southern states.

A recent ABC News poll found that 58% of Americans now support the legalisation of same-sex marriage, while 36% oppose it.

Currently, nine US states and the District of Columbia permit same-sex marriages. Eight other states allow civil unions or domestic partnerships.

In oral arguments next week, the US Supreme Court will address for the first time a possible right to same-sex marriage.

The issue for the nine justices on the first day is the constitutionality of California’s Proposition 8, the 2008 voter referendum that declared marriage a right only for a man and woman.

Earlier this month, President Obama said he believed banning gay couples from marrying went against the spirit of the US Constitution.

Thomson Reuters, which runs the Reuters news agency, said it supported efforts to legalise equal marriage in the UK, and around the world, in a statement last month.