WASHINGTON (Reuters) - Tension over the South China Sea highlights the need for the United States to maintain a strong Navy to serve as a deterrent, U.S. House Speaker Paul Ryan said on Thursday, criticizing the Obama administration for proposals he said would reduce the U.S. naval fleet.

U.S. House Speaker Paul Ryan (R-WI) calls on a reporter during a weekly news conference at the U.S. Capitol in Washington January 7, 2016. REUTERS/Jonathan Ernst

“This just shows that we need to have a strong Navy,”

Ryan said at a news briefing. “We should not have a president proposing to lower our ship count to pre-World War One levels. This means we need to have a strong military and a strong Navy, and a real foreign policy, which we do not now have.”

Three civilian Chinese flights have landed in recent days on a new island runway China has built in the disputed South China Sea, Pentagon spokesman Peter Cook said on Thursday.

“We’re concerned by all of these activities being conducted by the Chinese in disputed islands in the South China Sea,” Cook said.

In addition to China, Vietnam, Malaysia, Brunei, the Philippines and Taiwan have rival claims to territory in those waters. The first flight landed on the island on Saturday, and two flights landed on Wednesday, according to China’s Xinhua state news agency.

U.S. Republican presidential candidate Marco Rubio echoed Ryan’s call, saying that, if elected, he would sail U.S. ships through the contested South China Sea to challenge China’s claimed air and sea rights and work with other allies in the region.

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“We need to reinvigorate our Pacific military alliance, and that begins with the United States investing the resources necessary to rebuild our Navy,” Rubio, a U.S. senator from Florida, told Fox Business Network.

The assertion about the smallest U.S. Navy since World War One has become a popular talking point among Republicans, but has been widely discounted because contemporary ships are far more advanced and significantly larger than those in use a century ago.

Neither Ryan nor Rubio said how much they would allocate in resources for the Navy.

Republicans, who are seeking to take control of the White House from the Democratic Party in the November presidential election, have made U.S. President Barack Obama’s foreign policy a key campaign issue.

The United States has not taken a stance on the competing claims, and the Obama administration has repeatedly pressed for free, lawful navigation in the area.

“We again call for all claimants to reciprocally halt land reclamation, further development of new facilities, and militarization on their outposts and instead focus on reaching agreement on acceptable behavior in disputed areas,” State Department spokeswoman Anna Richey-Allen said.

Other top Republican lawmakers have criticized the Obama administration for not conducting more patrols in the South China Sea.

U.S. Navy officials have said the dispute could lead to a possible regional arms race.

Asked if he would intervene militarily to stop such Chinese plane landings if elected, Rubio said the United States needs to challenge China’s claims.

“We should reject their sovereignty over these areas and we should continue to fly our airplanes over it and sail our ships though it,” he said.