How to call testng.xml file from pom.xml in Maven

I'm using Selenium WebDriver, Eclipse, TestNG and Surefire plugin. I am not able to run testng.xml file from pom.xml. While I'm running pom.xml using mvn test it directly run the file which is in the src/test/java.

my pom.xml code is

<groupId>angel</groupId>
<artifactId>Angel</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>jar</packaging>

<name>Angel</name>  
<url>http://maven.apache.org</url>

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>   </properties>

<dependencies>
          <!-- Java API to access the Client Driver Protocols -->
 <dependency>
     <groupId>org.seleniumhq.selenium</groupId>
    <artifactId>selenium-java</artifactId>
    <version>2.21.0</version>
 </dependency>
  <!-- JExcel API is a java library which provides the ability to read, write, and                 modify Microsoft Excel spreadsheets.-->
  <dependency>
     <groupId>net.sourceforge.jexcelapi</groupId>
    <artifactId>jxl</artifactId>
    <version>2.6.10</version>
    </dependency>
   <dependency>
  <groupId>log4j</groupId>
  <artifactId>log4j</artifactId>
  <version>1.2.14</version>
</dependency>
 <!-- Java API for manipulate the Microsoft Excel Sheets.  -->  
 <dependency>  
<groupId>org.apache.poi</groupId>  
<artifactId>poi-contrib</artifactId> 
 <version>3.5-beta5</version>   
 </dependency>
 <!-- Java Mail API used to send Mails. -->   <dependency>             <groupId>javax.mail</groupId> 
 <artifactId>mail</artifactId>   <version>1.4.3</version>
</dependency>
<dependency>