Republican presidential candidate Sen. Ted Cruz upset a group of Muslim Americans after they were reportedly snubbed by his staff and refused entry to his office in Washington D.C. on Monday.

Cruz was campaigning in New York when a group of 14 Muslim Texans lobbied in front of his office in observance of "National Muslim Advocacy Day," according to Religion News Service.

They knew Cruz was out of town that day and would have been happy to meet with a member of his staff. However, U.S. Council of Muslim Organizations (USCMO) Secretary General Oussama Jammal said they were not allowed to enter Cruz's office and all of their efforts to set up another meeting failed.

"We are quite disappointed to see a presidential candidate refuse to meet with constituents from his own state," Jammal said. "This is a sad day for America."

Jammal said Cruz has already offended Muslims when he called for police surveillance of Muslim neighbourhoods. Meeting with them could have sent the message that the presidential candidate could indeed represent all Americans, he said.

When sought for a comment regarding the incident, Cruz's office did not respond.

Although the Muslim lobbyists were unable to meet Cruz or any member of his staff, they were able to meet with one-third of the U.S. House members and nearly half of all the senators.

The delegates of the USCMO discussed with the lawmakers such issues as Islamophobia, the federal Countering Violence Extremism programme, and the need to provide impoverished areas with healthy food.

Cruz has received the support and endorsement of several prominent Christians such as "Duck Dynasty" star Phil Robertson and well-loved African-American leader Bishop. E.W. Jackson of Fall Church.