US industrialists in the western region have expressed "serious concerns" to the Minister for Transport, Mr Brennan, about the state of infrastructure, including air, road and rail access.
They said the Government "must incorporate the needs of US industry into all regional development plans".
The company heads are also worried about the decline in graduates in the technology, engineering and physical sciences, tax treatment of research and development investment and the broad-band issue.
More than 570 US companies are represented in Ireland, employing over 89,000 people, and 44 of these are based in the west - employing 10,500.
Senior executives from the companies met the Minister for Transport in Galway yesterday as part of an American Chamber of Commerce (Ireland) initiative to identify and pursue regional development issues.
Among those represented were Hewlett Packard, America Power Conversion, Siebel Systems, Thermoking, Boston Scientific, De Care International, Coca-Cola, UTI Starguide and Medtronic.
Last July, the American Chamber called for a Yes vote in the forthcoming Nice Treaty referendum.
Mr Bernard Collins, the chamber's president, said Ireland's position as the traditional "Gateway to Europe" would be threatened by a second rejection of Nice.
A second rejection had the potential to marginalise Ireland within Europe, and this could have an impact on future investment decisions being taken by US companies looking to establish their presence in Europe, he said.
Speaking in Galway, the new chairman of the chamber's western region branch, Mr Rory O'Connor of Hewlett Packard, said US companies had faced some "challenging situations recently". However, they continued to make a major contribution to regional development - and to the overall success of the Irish economy.
"The Minister's visit to hear directly from the extensive US business interests in the west endorses the importance of the American-Irish economic partnership, which must be supported at all levels, nationally and regionally."
In a statement issued jointly yesterday with the American Chamber, the Minister said his new Department signalled the Government's intention to "intensify its efforts over the coming years to deliver a fully integrated, efficient and modern transport system countrywide".
Mr Brennan said good transport was critical for economic growth and competitiveness.
Investment in the national roads programme was now at an "all time high", and the provision for this year of over €1 billion was more than three times the 1997 level, and nearly twice that invested in 1999.
As part of its strategy to support US industry in the regions, the American Chamber of Commerce has established a number of regional groups to pursue specific issues.