Ed Woodward has told Manchester United fans to expect more signings as the club prepare to "do what it takes" to win the Premier League.
United limped to a top-seven finish last term as they meekly surrendered the title to rivals Manchester City, with David Moyes paying the ultimate price for their failure.
New manager Louis van Gaal is the man charged with bringing the good times back to Old Trafford and the Dutchman has already added midfielder Ander Herrera and full-back Luke Shaw to his squad.
The likes of Arturo Vidal, Kevin Strootman and Thomas Vermaelen have also been linked with a move to United and executive vice-chairman Woodward stated that money is available to further strengthen if Van Gaal deems it necessary.
"There is no fixed budget. Financially we are extremely strong, we have funds available," he told United's official website during the club's pre-season tour of the United States.
"Louis is the boss and is assessing what's going on but we have been in dialogue for some time about targets so there is a lot of work going on behind the scenes.
"We're continuing to move forward on some of those targets. So watch this space.
"The time he [Van Gaal] spends here as well [in America] he'll be able to assess more what he's got and continue to tweak the decisions if we need to.
"We want to do what it takes to win the title."
United's poor domestic performance means they will not take part in continental competitions this season, but Woodward does not expect that to deter potential signings.
"I've experienced a lot of conversations with agents and players and we are still a huge attraction to top football stars around the world - there is no doubt about that," he added.
"We've already invested in two new fantastic players."comments