SUNDERLAND remain confident of signing Belgium international Nicolas Lombaerts before the end of their tour of North America, but negotiations with Zenit St Petersburg continue to frustrate.

The Black Cats squad flew out of England yesterday morning ahead of a three-game trip that will see them play matches against Sacramento Republic, Club Pachuca and Toronto FC.

Dick Advocaat has completed deals for Sebastian Coates and Adam Matthews since the end of last season, but the head coach had hoped to have further new signings in place by the time he headed to America.

That has not been possible, largely because discussions with Zenit St Petersburg officials have proved more complex than had initially been anticipated.

Last week, Sunderland’s recruitment team, headed by sporting director Lee Congerton, thought they had finalised a €7m (£5m) agreement for Lombaerts, a 30-year-old centre-half who boasts 35 senior international caps.

However, Zenit returned to the table to demand a series of additional clauses that could result in Sunderland having to shell out more money over the course of Lombaerts’ deal, and as things stand, the Wearsiders have not been given formal permission to talk to the defender.

There is still a high degree of confidence that a new agreement can be reached, with further talks expected to take place later today.

Provided Lombaerts is signed at some stage this week, he will undergo a medical on Wearside before jetting out to link up with his new team-mates in the United States.

Advocaat is still hoping to add another three or four new faces this summer, with Dynamo Kiev forward Jeremain Lens remaining a leading target.

An initial €10m approach for the Dutchman proved unsuccessful, but Sunderland officials are willing to return to the negotiating table provided Dynamo chiefs display a willingness to settle on a fee that is regarded as a realistic proposal within the corridors of power at the Stadium of Light.

The Black Cats are also considering Everton winger Aiden McGeady as a viable alternative to Stewart Downing, who had been their initial preference as they look to strengthen their midfield.

Sunderland have discussed Downing’s position with the senior hierarchy at West Ham United, but the England international has outlined a preference to rejoin his former club, Middlesbrough, despite their position in the Championship.

Having missed last Thursday’s opening pre-season game against Darlington, Sunderland’s international contingent are back in training and available for this week’s opening tour game against Sacramento.

Costel Pantilimon, John O’Shea, Seb Larsson and Steven Fletcher have all travelled to the US, and should be involved in all three games.

Emanuele Giaccherini is also available, and having scored twice in Sunderland’s 4-2 win at Bishop Auckland’s Heritage Park, the fit-again Italian is determined to continue pushing his claims for a regular starting spot next season.

“Last season was really, really hard because I had to watch the games from the stands,” said Giaccherini. “That’s tough, but now we’re starting again and this season for me is so important.

“I will do my maximum to show the manager and everyone else my quality. If the manager chooses to play me, I will be available, and I will work as hard as I can to show I am ready.”