An index of confidence at small U.S. businesses rose in April to its highest in over a year as companies stepped up plans for hiring and investing, a survey released on Tuesday showed.

The National Federation of Independent Business said its Small Business Optimism Index rose 2 percentage points to 94.5, its highest since February 2011.

Pushing the labor component of the index higher, more firms reported they were planning to hire in the future.

"Hopefully, this performance will hold in the coming months," said William Dunkelberg, chief economist at the NFIB.

The NFIB said last week that companies added to payrolls in April, albeit at a slower pace of growth than in March.

Tuesday's report showed more companies also plan to spend money on things like buildings, land and machinery.